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ANN ARBOR, Ml 4B106 IB BEDFORD ROW, LONDON W CIR 4EJ. ENGLAND 7907370 M I L L E R * THDNAS LYNN DRIVE R KNOVLEDCE FOR AN INVENTORY OF C A I T I C A MOTOR VEHICLE OPERATORS AGE 65 AND OLDER IN INCHAN COUNTY, M ICH IGAN N IC H I C A N STATE UN1VERSI T V , Unlvwsfcv . Mcrtiflrrts ntcnwkxvfll io o n / u i h o a d . a ^ n A n io < i , M t 9106 P H .D ., 1978 PLEASE NOTE: In a ll cases this material has been filmed In the best possible way from the available copy. Problems encountered with this document have been Id e n tified here with a check mark . 1. Glossy photographs 2. Colored Illu s tra tio n s 3. Photographs with dark background 4. Illu stra tio n s are poor copy 5. Print shows through as the re 1s text on both sides o f page 6. In d istin c t, broken or smal 7. Tightly bound copy with p rin t lost 1n spine 8. Computer printout pager with In d istin ct p rin t 9. Page(s) J3Q lacking wfien material received, and not available from school or author p rin t on several pages _______ seem to be missing in numbering only as text 10. Page(s) fo il ows 11. Poor carbon copy 12. Not original copy, several pages with blurred type 13. Appendix pages are poor co p y __________ 14. Original copy with lig h t type 15. Curling and wrinkled pages 16. Other _________________ University. Miaonlms International 900 N ZEEB RD.. AN N ARBOR. M l 48106 *313) 761-4700 throughout AN INVENTORY OF CRITICAL DRIVER KNOWLEDGE FOR MOTOR VEHICLE OPERATORS AGE 65 AND OLDER IN INGHAM COUNTY, MICHIGAN By Thomas Lynn M ille r A DISSERTATION Submitted to Michigan State University 1n partial fu lfillm e n t of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Secondary Education and Curriculum 1978 ABSTRACT AN INVENTORY OF CRITICAL DRIVER KNOWLEDGE FOR MOTOR VEHICLE OPERATORS AGE 65 AND OLDER IN INGHAM COUNTY, MICHIGAN By Thomas L. M ille r Statement of the Problem Since the level o f c ritic a l driver knowledge among senior drivers is not known, i t was the purpose of the study to test and report the level of c ritic a l driver knowledge for four groups of Ingham County senior drivers: males with no accidents; females with no accidents; males with one or more accidents 1n the past two years; and females with one or more accidents 1n the past two years. An analysis of the data was made to determine (1) the level of c ritic a l driver knowledge 1n the senior driver population, (2) whether the mean c ritic a l driver knowledge scores o f males and females were equal, (3) whether the mean c r itic a l driver knowledge scores for senior drivers with accidents were equal to the mean c ritic a l driver knowl­ edge scores of senior drivers with no accidents 1n the past two years, and (4) whether the mean c ritic a l driver knowledge scores were equal for males with accidents, males with no accidents, females with accidents, and females with no accidents. Thomas L. M ille r Methods of Procedure The University of Michigan's Special Test Set was selected as the measure of c ritic a l driver knowledge for the study. The special test set items were written from the very and most cricical tasks identified 1n the HumRRo driving task analysis. The 246-item special test set was too large to be easily given to one person; therefore, i t was divided into three equivalent 82-item forms. Forms A, B, and C. A random sample o f 156 Ingham County senior drivers was s tr a ti­ fied into four study cells of equal size. Each person in the 39- subject study cells was randomly assigned to one of three equal size sub-cells. One form of the knowledge inventory, either Form A, B, or C, was randomly assigned to be administered to a ll thirteen subjects In each sub-cell. These knowledge inventories were administered during a two hour interview in the subjects' homes. Individuals' scores were transferred to mark-sense sheets for use in computer analysis. The Major Findings 1. Senior drivers were significantly deficient in c ritic a l driver knowledge. The mean score for senior drivers was 63 percent correct and the pre-set cutting score for non-defic1ent c ritic a l driver knowledge was 80 percent correct. The difference between the means was significant at the .05 level. 2. Twenty-five senior drivers or 16 percent of the sample were not deficient in c ritic a l driver knowledge as they attained or surpassed a score of 80 percent correct on the knowledge inventory. Thomas L. M ille r 3. The twenty-four most missed questions dealt with vehicle control, tr a ffic control signs and signals, license and vehicle registration, freeway driving, right and le f t turns, dimming head­ lig h ts , and drugs and alcohol. 4. The five topical divisions of the knowledge inventory with the highest mean item d iffic u lty scores were railroad crossings, bridges and tunnels, emergency situations and manuvers, skid control, driver licensing, and night driving. 5. The six topical divisions o f the knowledge inventory with the lowest mean item d iffic u lty scores were vehicle equipment, vehicle care and service, general highway driving, a n ti-th e ft laws, vehicle inspection, and accidents and accident reports. 6. Eighteen Items in the special test set were found to have an item discrimination value of 0 or less. 7. There was no significant difference between mean scores « of male and female senior drivers. 8. There was no significant difference between the mean scores of senior drivers who had been in one or more accidents 1n the past two years and senior drivers who had not been 1n an accident in the past two years. 9. The mean scores o f male or female senior drivers did not depend on th eir level o f accident experience. This study would not have been attempted without the encourage ment and support of a dedicated professional 1n the fie ld of tra ffic safety. This study 1s dedicated to Professor Robert F. Shrader of Miami University, Oxford, Ohio. "Doc" brought me Into the fie ld , and fired me with the dreams and desires necessary to attempt and complete a Ph.D. program 1n tr a ffic safety. Thomas L. M ille r 11 ACKNOWLEDGMENTS The w riter wishes to thank his chairman, Dr. Robert E. Gustafson, for his thoughtful counsel and guidance during the study and throughout the entire graduate program. A note of thanks also goes to Dr. Normal T. Bell; Dr. Robert 0. Nolan; and Dr. Donald L. Smith fo r th e ir time and assistance while serving on the guidance conmlttee of the study. A special thank you goes to Mr. Richard Austin. The coopera­ tion of Mr. Austin and his s ta ff at the Department of State made this study possible. Special appreciation 1s expressed to M1ss Shlrlee Johnson for typing the drafts of the study. Then there Is that special help only a wife can give. you, Suzanne. 111 Thank TABLE OF CONTENTS Page LIST OF TABLES.................................................................................................vl LIST OF F IG U R E S ..........................................................................................V11 LIST OF APPENDICES.................................................................................. v1ii Chapter I . THE PROBLEM................................................................................. 1 The P r o b le m ................................................................................ Definition of Terms .................................................................... Organization of Remaining Chapters ........................................ 3 6 8 I I . REVIEW OF RELATED LITERATURE ..................................................... 9 Identification of Senior Drivers and Their Problems . . 9 HumRRo Task Analysis ............................................................... 26 HSRI Item P o o l ................................................................................ 34 Summary.................................. . . .‘ ..........................................45 III. DESIGN AND METHODOLOGY ................................................................ 47 Population Selection ............................................................... 47 Sample Selection .......................................................................... 48 Study Variables .......................................................................... 50 Measurement o f the Variables ................................................... 52 Data Collection .......................................................................... 55 Instrument ...................................................................................... 57 Organization of Data ............................................................... 58 Summary..................................................................................................59 IV. ANALYSIS OF RESULTS ...................................................................... 60 The Sample Data .......................................................................... 60 Demographic Data .......................................................................... 65 Item D iffic u lty and Discrimination ........................................ 65 Analysis of Individual and Group Scores ............................. 70 Summary ............................................................................................ 75 IV Chapter V. Page SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS . . . . . 76 Summary of the S t u d y ..................................................................... 76 Methods of Procedure ............................................................... 77 F in d in g s ............................................................................................ 78 C onclusions...................................................................................... 80 Recommendations .......................................................................... 82 82 Recommendations for Further Research ................................... D is c u s s io n ...................................................................................... 83 BIBLIOGRAPHY APPENDICES ...................................................................................... 88 ..................................................................................................94 v LIST OF TABLES TABLE Page 4.1 S tra tific atio n of the Sample Frame: Accident—No Accident and Male—Female..................................................61 4.2 1-Way ANOVA Table of the Three Test Form Means 4.3 Mean* Median and Modal Ages of All Senior Drivers Contacted for Purposes of this Study ............................. 63 4.4 Age Range of Sampled Senior Drivers ................................... 63 4.5 Distribution of Sampled and Non-Sampled Senior Drivers . 64 4.6 Summary of Demographic Data by Participant—Nonpartlclpant and Accident—Non-accident Groups . . . 66 Rank Ordering of Top 24 Missed Items with Related Content Areas .......................................................................... 69 28 Topical Divisions of the Knowledge Inventory Rank Ordered by Their Mean Item D iffic u lty ............................. 71 Individual Test Scores by Group and Percent Correct . . 72 ........................ 73 4.7 • 4.8 4.9 4.10 2-Way ANOVA Table of the Four Group Means v1 . . . 62 LIST OF FIGURES Figure 1. Page Distribution of Item D iffic u ltie s and Discrimination In d ic e s ...................................................................................... v11 64 LIST OF APPENDICES Appendix Page A. Item D iffic u lty and Discrimination B. ................................ 95 Sample Driver Record........................................................... ' . 100 C. Letter to Mr. Stevens .......................................................... D. Letter to Ms. Owen and Newspaper A rtic le 102 ........................ 105 .......................................................... 107 F. Letter from Dean Hunter .......................................................... 109 E. Subject Contact Letter G. Letter from Mr. A u s t i n .................................................................I l l H. Demographic Data Sheet I. .......................................................... Items from Form A, B, and C of theKnowledge Inventory. v 111 113 115 CHAPTER I THE PROBLEM Past research has Identified the senior driver population 12 3 as a high accident risk, problem driver group. ’ * Senior drivers are involved 1n more accidents for th eir exposure than any other group, except youth, under age 25/ They are also more lik e ly to die or suffer serious Injury when Involved in a crash. 5 In response to high accident experience, the senior driver either stops driving prematurely or Ignores the obvious and continues to drive, a hazard to himself and others. Both arbitrary lim itations of senior citizen mobility In this highly automobile-dependent society and suffering caused by crashes involve great social costs. ^U.S. Department of Transportation, The Driver Education Evaluatlon Proqram (DEEP) Study (Washlnqton. D.C.l Government Pr1nt1nq O ffice, 1975), p7 )9. E. A llgaler, "Accident Involvement of Senior Drivers," T ra ffic Digest and Review (March 1965), p. IB. 3 E. Klebel, "Age and Driver Fitness," Proceedings ference on the Aging Driver, American Medical Association and American Association of Rotor Vehicle Administrators (Morton Grove: Health and Safety Associates, ^97^)7 p. $9. ^T. W. Planek and R. B. Overand, "Profile of the Aging Driver," T ra ffic Safety (January 1973), p. 2. 5S. P. Baker and W. U. Spitz, "Age, Disease and the Driver," Proceedings Third Triennial Congress on Medical and Related Aspects of Motor Vehlcle AccfdentsT International Association for Accident and T ra ffic Medicine (Ann Arbor: Highway Safety Research In s titu te , T9?l), p. 40. More recent research 1n Florida, fi Michigan 7 and Virginia B provided driver refresher classes and materials for a specific senior driver population. Their efforts to identify the level of senior driver knowledge did not go beyond the needs of th eir specific target population. Therefore, I t appears that th e ir results could not be applied to the general senior driver population. In short, no one was sure of what senior drivers did and did not know. The Inventory developed for use 1n this study was designed to co llect Information on the amount and scope of c ritic a l driver knowledge and its correlation to specified demographic data 1n the senior driver population. This Information was seen as being useful to educators and researchers In developing curriculum and study pro­ grams dealing with senior drivers. I t should provide the necessary information for development of senior driver refresher courses with wide scale ap p lic ab ility. J. L. Crosier, "The Development of Guidelines for a Driver Improvement Program fo r Residents of a Retirement Community" {Ph. D. dissertation, New York University, 1972). 7 L. A. Pastalan, e t a l . , Street and Highway Environments and the Older Driver (Ann Arbor: In s titu te of Gerontology, 1975). g A. J. McKnight and M. Green, Safe Driver Knowledge Dissemi­ nation and Testing Techniques, Final Report, Volume Z (Springfield. V irg in ia: National Technical Information Service, 1977). 3 The Problem Statement of the Problem Deficient driver knowledge in motor vehicle operators age 65 and older has not been clearly defined. More sp ecifically, to date there has not been a randomly selected group of motor vehicle operators age 65 and older tested for level of driving knowledge with an Instrument based on c ritic a l driving tasks. Purpose of Study The purpose of this study was to Identify areas of deficient c ritic a l driver knowledge in the Ingham County, Michigan driving popu­ lation age 65 and older. A second purpose of this study was to compare the mean c ritic a l driver knowledge level for the following four groups of Ingham County drivers age 65 and older: males with one or more accidents 1n the last two years; males with no accidents 1n the las t two years; females with one or more accidents 1n the la s t two years; and females with no accidents 1n the la s t two years. The problem was Investigated by answering the following research questions: 1. What 1s the level of c ritic a l driver knowledge In the senior driver population? 2. Are the mean c ritic a l driver knowledge scores of males equal to the mean c ritic a l driver knowledge scores of females? 3. Are the mean c ritic a l driver knowledge scores of senior drivers with accidents equal to the mean c r itic a l driver knowledge scores of senior drivers with no accidents? 4 4. Will the mean c ritic a l driver knowledge scores be equal for: males with accidents; males with no accidents; females with accidents; and females with no accidents? Hypotheses The four hypotheses Investigated in the study were: 1. Senior drivers would not show a c ritic a l driver knowledge level of 80 percent correct. 2. 3. Hq: S. D. p H-j: S. D. p t 80 b 80 The mean scores for male and female senior drivers would not be equal. The the for two Hq: p Mb p F H1: p Mf p F mean scores for senior drivers with no accidents In past two years would not be equal to the mean scores senior drivers with one or more accidents 1n the past years. HQ: p ACC = p No ACC H] : p ACC f p No ACC 4. The mean scores for: females with no accidents; females with one or more accidents 1n the past two years; males with no accidents; and males with one or more accidents 1n the past two years would not be equal. H0 : P Fn * V Fy - „ Hn - M My p Fn f p Fy t P Mn f p My Importance of the Study Groups of senior drivers have shown a fa ir ly consistent range of problem driving behaviors. However, no studies have been made using 5 random sampling of subjects and a comprehensive 11st of c ritic a l driving knowledge to discover the level of c ritic a l driver knowledge 1n the senior driver population. I t was f e l t this study could make the following significant contributions to the fie ld of tra ffic safety: 1. The level of deficient c r itic a l driving knowledge w ill be Id en tified , assisting educators and curriculum planners In "establishment of special driving clinics for elderly g drivers," as recommended by the 1975 (DEEP) study. 2. Future researchers Into psychomotor and attltu dinal aspects of senior driver problems w ill be provided with the areas of c ritic a l driver knowledge as a reference point from which to begin th eir projects. 3. The results of this study w ill Indicate the main and Interaction effects of sex and recorded accident experlence on senior driver mean scores of c ritic a l driver knowledge. Limitations of the Study The data from this study were lim ited 1n th eir direct appli­ cation to the senior driver population of Ingham County, Michigan, the source of subjects fo r this study. ®U.S. Department of Transportation, The Driver Education Evaluatlon Program (DEEP) Study (Washington, D.C.1 Government Printing O ffic e ," !975), p. W ;------- 6 The results of this study were limited to being only as good as the research documents that preceeded 1t. well the Item Bank was constructed. One might question how However, the Item Bank 1s the only d e fin itiv e source authority of Its kind. Great e ffo rt was made to make the document a complete, yet workable tool. Accident records, were, for many reasons, found not to be complete. The data from this research was limited to the unknown level of completeness of the Michigan accident reporting system. Non-Engl1sh speaking persons, age 65 and older, with a valid Michigan operator's license were rare and, as they were dropped from the study, remain a lim itatio n of this study. I f the non-part1c1pants had been Included 1n the sample they would not have been expected to bias the sample 1n any systematic manner. Demographic data were collected and compared for a ll persons contacted In this study. Definition of Terms Accident For the purpose of this study an accident was defined as any notation of accident on an Individual's Michigan driver record. C ritical Driver Knowledge Those Items rated as very and most c ritic a l by the HumRRo driving task analysis, fo r which Items were written and tested by the Special Test Set of the National Item Bank for Tests of Driving Know­ ledge, were classed as c ritic a l driver knowledge. 7 Deficient C ritical Driver Knowledge For the purpose of this study deficient c ritic a l driver know­ ledge was defined as an Individual score below 80 percent correct on the knowledge Inventory. HSRI Item Bank The National Item Bank for Tests of Driving Knowledge 1s a document containing a group of 1,313 test Items—hereafter referred to as the HSRI Item Pool. These items were developed from the HumRRo driving task analysis, a review of the lite ra tu re and current driving knowledge tests. The items re fle c t the very and most c ritic a l tasks Identified by the HumRRo task analysis. The Items were tested with Iowa driver education students, and U.S. Coast Guard recruits to collect psychometric, normative and validation data for each question. HumRRo Driving Task Analysis The HumRRo study used In this project was Driver Education Task Analysis. Volumes I - IV , by A. James McKnlght, et a l . , of Human Resources Research Organization, (HumRRo), Alexandria, Virginia, published 1n March, 1971. Senior Driver For the purpose of this study a senior driver was defined as any licensed driver residing 1n Ingham County, Michigan, born on or before January 1, 1913. 8 Special Test Set The Special Test Set was a representative group of 246 Items from the National Item Bank for Tests of Driving Knowledge on which v a lid ity and r e lia b ilit y data were collected from four classes of Michigan driver license applicants. Organization of Remaining Chapters Chapter I I w ill contain a review of the lite ra tu re on the senior driver and his driving problems, a description of the HumRRo study and a description of the Item Bank. The sample collection methods, design and methodology of the study w ill be found 1n Chapter III. Deficiencies 1n c ritic a l driver knowledge and the mean level of c ritic a l driver knowledge found 1n four groups of senior drivers w ill be presented 1n Chapter IV. Chapter V w ill contain the summary, conclusions, recommendations, recommendations for further research and a discussion. CHAPTER I I REVIEW OF RELATED LITERATURE This chapter presents a review of the lite ra tu re related to this study of senior drivers. The review of the lite ra tu re was divided Into three related areas dealing with the Identification of the senior driver and his problems, the HumRRo study and a discussion of the HSRI Item pool and Its special tes t set. Identification of Senior Drivers and Their Problems The lite ra tu re on the senior driver reviewed here covers his Id en tificatio n , Increasing population s ta tis tic s , and driving-related problems. The senior driver 1s found to be Increasing In number, with many driving related problems for which no re lia b le test data have been collected. Identification of the Senior Driver The senior driver 1s generally accepted as that person over age 65 who holds a valid driver license and drives a motor vehicle. 1 2 Studies by Bloomfield and McDonald both used age 65 to Identify ^G. J. Bloomfield, "A Descriptive Study of Senior Driver Accident Records 1n the State of Michigan by Age Group, Sex, Urban and Rural Residency" (Ph.D. dissertation, Michigan State University, 1971), p. 18. ^H. L. McDonald, "Problems of a Select Group of Older Drivers" (Ph.D. dissertation, Michigan State University, 1970), p. 34. 10 senior drivers. H is to ric a lly age 65 has been used in Germany, Eng­ land and the United States fo r retirement purposes as early as the 1870s. Planek further supported the use o f age 65 as the dividing lin e fo r senior drivers when he said: While 65 1s s tr ic tly an a rb itra ry point in terms of the human organism's aging process, 1t Is used so widely to produce changes 1n the organism's environment that I t 1s a good choice. At the age of 65 retirement begins, income usually decreases, social security benefits become available, and a ffilia tio n s begin to change. These exter­ nal factors cause, in turn. Internal changes in the organ­ ism. I t may be that some o f the external changes forced upon an Individual reaching 65 are instrumental 1npro­ ducing some o f the ch aracteristic differences that are attributed to those "over 65". I t also may be that these external changes contribute to some o f the acci­ dent producing situations 1n which people over 65 find themselves.4 5 6 Volumes such as Accident Facts and Michigan Driver S ta tis tic s displayed th e ir data Into fiv e year groupings, making drivers age 65 and older easily id e n tifie d . Drivers over age 65 w ill show a change in driving exposure, which Indicates they are Involved 7 in a d iffe re n t type o f driving from those under age 65. ^T, W. Planek and R. B. Overend, "P ro file of the Aging D river," T ra ffic Safety (January 1978), p. 1. 4T. W. Planek, M. C. Condon, and R. C. Fowler, An In v es ti­ gation o f the Problems and Opinions o f Aged Drivers (Chicago: National Safety Council Research Department, Report No. 5/68, 1968), p. 3. ^National Safety Council, Accident Facts, 1975 (Chicago: The Council, 1975). ®State of Michigan, Michigan Driver S ta tis tic s Report 6 (Lansing: Secretary of State, 1973). 7 Planek, An Investigation o f the Problems and Opinions of Aged Drivers, p. 73-74. 11 Blrren pointed out: Human chronological age represents d ifferen t points on a young-old continuum where biological* psychological, or sociological viewpoints must be considered somewhat Indepen­ dent. In each of these areas the Individual "ages” at a d ifferent rate and according to a characteristic pattern. All these must beconsidered when discussing performance of a task such asdriving.® Age 65 was a convenient point to begin data collection on senior citizens. However, while age 65 was convenient, 1t remained an arbitrary measure which didn't give an accurate picture of an Individual's physical and mental capabilities. When considering groups of subjects the traditional beginning of "senior" status was age 65. Senior Driver Population Today 10 percent of the population, are over age 65. o or about 20 m illion people, Senior citizens, as a group, are expected to Increase 1n numbers u n til the end of the century. Some estimates put the senior citizen population as high as 25 percent by 1999. An a rtic le by Brotman indicated: A large aged population 1s a rather new phenomenon, new to this century. Since 1900, the 65-1- population has grown much faster than the rest of the population and the 75+ segment has grown even faster. At the turn of the century, there were 3 m illion older persons, every 25th American; today, there are 20 m illion, every 10th American. The 65+ group is 6>s times as large as 1n 1900: the under o J. E. Blrren, "Research on the Psychological Aspects of Aging," Geriatrics (1963), p. 18. 9 Administration on Aging, The Aging Person: Needs and Services (Washington, D.C.: U.S. Department of Health, Education and Welfare, 1970), p. 1, 12 65 group is only 2h times as large. I f present very low b irth rates continue, by the year 2000, we w ill have almost 29 m illion older Americans, every 9th American. This dramatic Increase does not mean that older people are liv in g very much longer, ju st that more people are reaching old age. The real Increase 1n l i f e expectancy has occurred In Infancy and childhood.10 In an a rtic le by Fowles the aging population was explained as follows: Because of Increases 1n longevity 1n the past several decades and generally low f e r t i l i t y since the 1920s (except for the post World War I I "baby-boom" e ra ), the elderly are becoming an Increasing proportion of our nation's popula­ tion. The demographic characteristics of the elderly such as age, sex, and race, have been undergoing marked shifts for many years and current projects Indicate that these trends w ill most lik e ly continue to the end o f this century.1* In hearings before the 93rd Congress 1t was emphasized that: . . . during the next 27 years the expected to Increase markedly. By I t Is estimated that anywhere from Americans w ill have had th eir 65th elderly population 1s the turn of the century 40 million to 45 million birthday.12 This Increase 1n senior citizen population 1s expected to bring with 1t an Increase 1n the number and proportion of senior drivers. For as Wiener stated: The s c ie n tific and medical community must be encour­ aged to apply Its talents and techniques to this problem which w ill become more severe as the absolute number and l^H. B. Brotman, "The Fastest Growing Minority: American Journal of Public Health (March 1971), p. 250. The Aging," ^D . G. Fowles, "U.S. 60+ Population May Rise 31% to 41 M illion by Year 2000," Aging (June-July 1975), p. 14. CU.S. Congress, Senate, The Special Committee on Aging, The Needs of Elderly People, Hearing, 93rd Congress, 1st Session, June 19, 1973 (Washington, D.C.: Government Printing O ffice, 1973), p. 7. 13 percentage of over-60 persons 1n the U.S. continue to grow, and the percentage of over-60 drivers grows even faster. The last generation of non-driving elderly 1s dying o ff now. The senior citizen 1s re la tiv e ly mobile 1n that only 3 to 5 percent of the elderly were permanently In s titu tio n a liz e d .^ The proportion of senior citizens 1n the population 1s ex­ pected to more than double 1n the next 22 years. This new popu­ lation of elderly w ill be accustomed to maintaining th eir existing level of mobility. This Increase 1n numbers w ill burden our already limited mass transportation fa c ilitie s and place an even greater need for thp Individual to provide his own means of mobility. This w ill, 1n turn, Increase the proportion of active drivers 1n the senior citizen population. This Increase, coupled with the Increased proportion of senior citizens 1n the general population, w ill show up as a large Increase 1n the senior driver population. Driving-Related Problems Three major areas were Identified 1n the lite ra tu re as causing problems for the senior driver. These areas were: medical and physical factors associated with aging, temporary personality dis­ orders, and lack of tr a ffic knowledge. Medical, physical, ^3E. L. Wiener, “Loss of Mobility 1n an Automotive Society," Proceedings of the National Conference on the Aging Driver {Morton Grove: fieaftharTdT SaYety Associates, 1374), p. 53. 14L. S. Libow, "Older People's Medical and Physiological Characteristics: Some Implications fo r Transportation," Trans­ portation and Aging: Selected Issues, Proceedings of the In ter­ disciplinary fforksnopon Transportation and Aging (Washington. D.C.: Government Printing Office, May 1970), p. 14. 14 personality and psychomotor disorders were beyond the scope of this study. This study dealt sp ecifically with the Id entificatio n of c ritic a l driver knowledge. This review describes attltu d ln a l and psychomotor problems to Indicate th eir connection as part of the overall problem. Medical and physical problems. I t was beyond the scope o f this review to identify each specific medical and physical prob­ lem of senior drivers 1n d e ta il. This review considered the prob­ lems most often cited 1n the lite ra tu re as being d irec tly related to driving performance. There existed basic health problems which occurred with Increased frequency among the aged. Ignorance of the effects of these health problems, when associated with the driving task, caused poor performance by senior drivers. These conditions were listed by Sears as being poor vision, coronary artery and related heart problems, and mental and neuromuscular degeneration.^ Aging was Inevitably accompanied by progressive impairment of vision. Rodsteln stated: With age, the pupils become smaller, the transparency of the media 1s reduced, the refracting mechanism Is less powerful, and the retina and central nervous system are less e ffic ie n t. As these capabilities change, presbyopia with a loss of the near fie ld vision, d iffic u ltie s 1n descending steps and curbs when bifocal lenses are used for correction, a steady need fo r increased Illumination, a progressive loss of visual acuity, and a decrease 1n 15k . A. Sears, "S p ecific Medical Considerations," Proceedings o f the National Conference on the Aging D river (Morton Grovel H ealth and Safety Associates, 1974), p. 2 7 . 15 night vision develop. Taking the optimum visual acuity, contrast, and speed o f vision in the normal 20 year old eye as optimal, a t age 45 brightness must be increased by 50%, by 100% In the la te 50's and by 333% at 80 to achieve the same optimal lev els.'® Planek, Condon and Fowler^ found increasingly lim ited vision as an age-related problem. Poor glare recovery and lim ited night and oerlpheral vision were found to be age-related problems, causing 18 misleading visual information and side-on co llis io n s . Forbes, Vandosdall, Pain and Bloomqulst found age-related decreases in 19 visual acuity. Coronary artery disease and related heart problems were found to be age-related. Baker and Spitz found severe narrowing of the coronary arteries 1n about h a lf o f the white males over 50. 20 DIMaio found that 87.2 percent of drivers studied died o f occlusive M. Rodstein, "Pathological and Physiological Changes in Older Adults: Effects on Drivers and Pedestrians," International Association fo r Accident and T ra ffic Medicine, Proceedings Third Triennial Congress on Medical and Related Aspects of Motor Vehicle Accidents (Ann Arbor: Highway Safety ftesearch In s titu te , 1971), p. 57. 17 Planek, An Investigation o f the Problems and Opinions of Aged Drivers, p. 2T. 18 Rodstein, op. c l t . , p. 56. 19 T. W. Forbes and others. Low Contrast and Standard Visual Acuity Under Hesopic and Photoolc illum ination ICast Lansing: Continuing Education Service, June 1968), p. 18. 20 S. B. Baker and W. U. S p itz, "Age, Disease and the D river," Proceedings of the Third Triennial Congress on Medical and Related Aspects of Motor Vehicle AccfdentsT international Association for Accident and T ra ftlc Medicine (Ann Arbor: Highway Safety Research In s titu te ', 157T), p. 38.--------- 16 coronary arteriosclerosis. 21 Planek stated that conditions such as cardiovascular disease were associated with Increased accidents and 22 violations. Brown found arrhythmias the most serious problem for 23 senior drivers, as they caused Hght-headedness and blackouts. The widespread Incidence of heart and circulatory problems among the senior driver population led the researcher to suspect that cardiovascular problems occurred In combination with less dramatic conditions causing serious deficiencies In driver performance, Mental and neuromuscular degeneration were also age-related. Mental degeneration or s e n ility included such areas as: 24 Ir r it a b ilit y ; Impatience; forgetfulness; short attention span; and emotional lia b ilit y . These conditions In th eir gross form were easy to identi25 fy and prevented a person from obtaining a driver's license. "Aging brings on loss of muscular s k ill, strength and coordination." 2fi 21 D. J. DiMaio, "A Survey of Sudden, Unexpected Deaths 1n Automobile Drivers," Proceedings of the Third Triennial Congress on Medical and Related Aspects o j Motor Vehicle Accidents: International Association for Accident and tr a ffic Medicine (Ann Arbor: Highway Safety Research In s titu te , lS 7 l), p. 75. 22 Planek, An Investigation of the Problems and Opinions of Aged Drivers, p. 4(T 23 A. J. Brown, "Cardiovascular Problems," Proceedings of the National Conference on the Aging Driver (Morton Grove: Health and Safety Associates, 1974), p. 3dT 24 Rodstein, op. c 1 t., p. 58. 25W. K. K e lle r, "Mental and Emotional Aspects," Proceedings o f the National Conference on the Aging D river (Morton Grove: Health and Safety Associates, lS M ) , p. 31, 2fi Rodstein, loc. c it . 17 Rodstein also found: Movement of the head backward and upwards and rotation of the neck compresses the vertebral arteries and causes dizziness, faintness and syncope. One can well Imagine the effects on the aged motorist o f looking Into the rear and side view m ir r o r s .27 Senior drivers are having a harder time adapting to tr a f fic situations as they age. Planek stated that behavioral deficiencies occurred primarily when the environment p1aced..£Xtra demands on the 1nd128 vldual. The senior driver exhibited slowed reaction time, loss of muscle s k ill and a slow response to sudden change of plan which 29 Increased the risk of accidents. Medical problems Influenced a senior driver's a b ility to control a vehicle 1n varying degrees. Medical problems were readily observable 1n some people while for others they were hidden. Medi­ cal conditions represented one aspect of senior driver problems. The presence of these often unseen medical conditions had to be considered as part of the overall problem being experienced by senior drivers. Personality factors. Senior drivers, lik e any other drivers, are sometimes subject to temporary personality disorders, but senior drivers have many more opportunities to become frustrated with the quality of their lives. This Increased frustration Is translated 27 'Rodstein, loc. c1t. 28 Planek, An Investigation of the Problems and Opinions of Aged Drivers, p. 3(>. - 29 'Rodstein, loc. c it . 18 to Irratio n al and unsafe driving behavior. As Lawton remarked: Older persons are often surrounded by the frank h o s tility of youth for elderly authority. They respond 1n kind with h o s tility , fear, hate or aggressiveness, so that often the emotional state of the elderly 1s a seething ferment of disturbance. These may dominate th e ir consciousness to the exclusion of reason and to the obliteration of training and experience, thus removing them from the category of safe drivers.30 These personality disorders often take concentration away from the driving task, making the aging driver probably more frequently 31 affected by lack of alertness. Weygandt observed that the senior driver suffered from an attltu dlnal rig id ity . This Is a condition which manifests It s e lf 1n almost total concentration on the desti32 nation to the exclusion of highway conditions. This narrowing mental view of the highway 1n combination with the physical problem of tunnel vision was suggested as the source of fa ilu re to yield right of way violations by senior drivers. All drivers have temporary personality disorders which affect th e ir driving. Senior drivers have more opportunities to be frus­ trated and to display frustration-linked driving responses. A ttl­ tudlnal d iffic u ltie s must be considered as part of the overall problem being experienced by senior drivers. 30A. Lawton, "The Doctor Looks at the Older Driver," T ra ffic Safety (October, 1974), p. 44. 31W. A. Mann, "Problems of the Aging Driver," The Proceedings of the NorthCarolina Symposium on Highway Safety (Chapel H ill: University of tlorth Carolina Press, 1973), p. 44. 32J. L. Weygandt, "Role o f the Family Physician," Proceedings o f the National Conference on the Aging D river (Morton Grove: Health and Safety Associates, 1 9 /4 ), p. 19 Lack of t r a f f ic knowledge. All the lite ra tu re that mentioned senior drivers and t r a f f ic knowledge placed them at the low end of the scale. Reasons suggested fo r th is low level of t r a f f ic knowledge were lack o f formal t r a f f ic education and the reduced a b ilit y to recall Information. These reports used d iffe re n t populations fo r th e ir data co llectio n; and the reported Information on specific driver knowledge deficiencies did not agree from report to report. Senior drivers 1n this study would have been born In 1913 or before. They would have begun to drive by age 14 to 20—or by 1927 to 1932. This time pre-dates d river education e ffo rts . It was reasonable to assume, then, that senior drivers might show a lack of knowledge of t r a f f ic laws and safe driving practices. These i results would be the same expected fo r any untrained drivers. Mann stated: We tested a considerable1number of older drivers and found that fo r some questions over 50% did not know the the correct answer.33 Waller suggested that: because a ll of the organic and psychological changes 1n the eld erly 1n fa c t place them on a new learning curve fo r driving, ju s t as the young d rive r 1s on a learning curve. The young d riv e r, however, 1s lik e ly to s ta b iliz e a fte r about two or three years, while the older driver remains on a learning curve from about age 55 u n til he ceases d riv in g .3^ 33 Mann, op. c 1 t., p. 45. 34J. A. W aller, "Medical Lim itations and the Elderly D river," Proceedings of the National Conference on the Aging Driver (Morton Grove: HeafthTnd Safety Associates, '1974}’, p. 75, 20 Senior drivers are also subject to forgetting things and becoming less able to recall Information rapidly. Reader stated that senior drivers: need additional time to solve problems under fast-moving circumstances that tr a ffic produces to make the elderly person unsafe.35 And Klebel found that " . . . older persons need more time to organize 36 and process Incoming Information." Planek stated that " . . . recog37 nlzatlon memory does not decline with age while recall memory does." A 1973 document from the Michigan Secretary of State's office gave Older Michigan Driver's Renewal Results. This document showed overall renewal scores 1n fiv e year age groupings for drivers: age 50-54, 55-59, 60-64, 65-69, and 70 and up. an age related decrease In driver knowledge. The data reflected In other words, the older the driver, the more answers they missed. The pattern o f deficient driver knowledge did seem to vary but concluded that male senior drivers had an overall higher mean score than female senior d rive rs .38 G. C. Reader, "Keynote Address," Proceedings of the National Conference on the Aging Driver (Morton Grove: Health and Safety Associates, 19^4), p. 10. 38E. Klebel, "Age and Driver Fitness," Proceedings of the National Conference on the Aging Driver (Morton Grove: Health and Safety Associates, 1974), p. 42. 37 Planek, An Investigation o f the Problems and Opinions of Aged Drivers, p. 33. 38 Michigan Secretary of State, "Older Driver's Renewal Results," Lansing: Michigan Secretary of State, 1973, (mimeo­ graphed), p. 1. 21 In a Florida retirement center study, Crosier found senior drivers lacking 1n tr a ffic knowledge. 39 His use of the McGlade Road Test found senior drivers with below average knowledge in the areas of emergency driving situations, stopping distance and alcohol. The area of automobile control was also reported at the Inadequate know­ ledge le v e l/® The data for this study was drawn from one retirement center 1n Sun C ity, Florida. These results cannot be generalized to the senior driver population of Ingham County, Michigan. However, these findings w ill Indicate possible outcomes for this research and should not be Ignored. Senior driver knowledge deficiencies were found by Pastalan In a 1975 Ann Arbor study of Street and Highway Environments and the Older Driver. The knowledge areas pertaining to failu re to yield rig h t o f way, improper procedures for lane change, turning, passing and backing, and stop and yield signs were Identified as problem 41 areas for senior drivers. This study was done with the voluntary cooperation of six senior drivers from a retirement center in Ann Arbor, Michigan.42 The sample size and selection method did not allow these these results to be generalized beyond the six persons 39 J. L. Crosier, "The Development of Guidelines for a Driver Improvement Program fo r Residents of a Retirement Commmity," Ph.D. dissertation, New York University, 1972), p. 69. 40Ib id ., p. 9. 41 L. A. Pastalan, et a l . , Street Highway Environments and the Older Driver (Ann Arbor: In s titu te of Gerontology, 1975), pTTT 42Ib 1 d ., p. 10. 22 in the study. This was one of the few studies where specific areas of deficient driver knowledge were reported for senior drivers. In an unpublished study at Michigan State University, Nolan, et a l . , founddeficient driver knowledge 1n senior drivers. A "Senior Driver Project" was developed and presented to 25 volunteer members of a retirement center 1n East Lansing, Michigan. The Mann "Adult Driver Test" was used to find deficiencies in the following knowledge areas:* hydroplaning, new signs, search patterns for lane change and turns, freeway entrance and e x it procedures, stopping and passing distance, one way street procedure and stop and yield signs. The pretests were used to construct course curriculum for that specific group. AO The data 1n this study represented knowledge deficiencies of the 25 volunteers at Burcham H ills Retirement Center which 1s populated by senior citizens who have a high level of education and economic resources. This population did not repre­ sent a random selection of the drivers 1n Ingham County, Michigan. However, the results of this study were of use in determining possible outcomes for this research project. An unpublished 1971 study by Hayes at the Michigan Secretary of State's o ffice listed the fiv e most occurring violations for senior drivers as: fa ilu re to y ie ld , fa ilu re to drive minimum speed, fa ilu re to stop for school bus. Improper turns and unsafe backing.^ ^ R . 0. Nolan, et a l . , "Senior Driver Project" (unpublished research report, Data Tally Sheet #1), East Lansing: Michigan State University, 1975. 44 J. Hayes, "Senior Citizen Aid Program," Lansing: Michigan Secretary of State, 1973 (mimeographed), p. 1 23 Being ticketed for a violation Is at best a random occurrence, but these five most occurring Improper actions can be considered as some Indication of the direction of deficient knowledge, s k ill or attitude 1n the senior driver population. Lack of driver knowledge was to some degree a component of these violations. Therefore, these knowledge areas were Indicated as possible problems for senior drivers and were not Ignored as possible outcomes for this study. A 1973 document from the Michigan Secretary of State's office reported an Analysis o f Older Driver Answers on Renewal Test Questions. These 29 Items were ranked by question d iffic u lty up to 99 percent correct. They were then compared with the results of a 1970 study of the same Items. The 1973 Items were the results of an audio/visual test-taking device, and the 1970 Items were presented 1n pencil and paper format. Questions missed by 20 percent or more of the 1970 and 1973 renewal drivers were reported as: freeway entry, flashing green arrows, when to dim lig h ts, maximum speed lim its and when to use turn signals. These results were suspect because 1t was late r found that older drivers were having a d iffic u lt time understanding and using the audio/visual test machines. with the test Instrument. The results were confounded These results could not be considered a d efin itive answer to deficient driver knowledge 1n senior drivers, unless one assumed that a ll driving knowledge could be Inventoried by 29 questions; but the results gave an Indication of where problems 45 Michigan Secretary of State, "Analysis of Older Driver Answers on Renewal Test Questions," Lansing: Michigan Secretary of State, 1973, (mimeographed), p. 1. 45 might occur. The question s t i l l remained, however, 1f errors were due to a lack of understanding of the testing Instrument, a lack of driving knowledge, or Insufficient knowledge of Items being tested. In a 1977 study to develop Virginia driver manuals for drivers age 55 and older, a 20 Item driver license examination was admin47 Istered to 8,000 drivers. The results Indicated lack of driver knowledge 1n these areas: Identificatio n and Interpretation of signs; defensive driving; textbook Information; and not looking to the rear 48 when backing. The 20 Item Instrument, while based on the HumRRo task analysis, did not represent a comprehensive examination of driver deficiencies. Only items rated as being c ritic a l to senior 49 drivers were tested. The population used 1n the Virginia Study, age 55 and older, was not the same as the target population of this research. The results of the Virginia study were helpful in 1nd1« eating the direction of knowledge deficiencies for this research, but could not be considered an outline o f the problems of drivers age 65 and older 1n Ingham County, Michigan because two d ifferen t age populations were sampled and tested. Also the use of a 20 Item examination lim ited finding deficiencies to only the 20 areas tested. The two severe lim itations of the Virginia study prevented the re­ sults from being generalized to the senior driver population of Ingham County, Michigan. A. J. McKnlght and M. Green, Safe Driver Knowledge Dlsseml nation and Testing Techniques. Final Report. Volume 2 (Springfield. Virginia: National Technical Information Service, 1977), p. 10. 48Ib 1 d ., p. 27. 49Ib 1 d ., p. 111. 25 I t 1s clear that the senior driver lacks driver knowledge. However, while a ll sources agreed the senior driver suffers from a lack of tr a ffic knowledge, no two sources agreed on what areas they defined as lacking. Each report reviewed presented serious problems with inadequate or inappropriate sampling, confounded results, or in ­ su fficien t test questions to yield a comprehensive inventory of driver knowledge deficiencies. Four general areas of driver knowledge d e fi­ ciencies were reported as: lack of automobile control 1n many forms, poor emergency driving, fa ilu re to y ie ld , and poor judgment of stop­ ping and passing distances. These general areas provided an Indication of where knowledge deficiencies might occur. They did not, however, provide Identification of specific c ritic a l driver knowledge d e fi­ ciencies. In each case the reported results could not be generalized to drivers age 65 and older In Ingham County, Michigan. Summary This section Identified the senior driver as being age 65 or older, and part of a group that 1s and w ill continue to experience growing driving problems as this age group expands. The problems they experienced were caused by an undefined combination of medical, psycho­ logical and cognitive d e b ility with no two reports agreeing on what knowledge was lacking. Design and sample problems of prior research lim ited the usefulness of th e ir results. The task analysis and Item pool were documents central to this research. The remaining two parts of this chapter w ill describe the HumRRo task analysis and the Highway Safety Research In s titu te Item pool with Its special test set. 26 HumRRo Task Analysis This section defines the Human Resources Research Organization (HumRRo) task analysis. I t also describes the organization, construc­ tion and r e lia b ility findings for the HumRRo study. The last part of this section Identifies other users and the relevance of the HumRRo study for this project. Defined The HumRRo task analysis was developed by the Human Resources Research Organization of Alexandria, V irginia. I t 1s a document In four parts, describing a systematic analysis of driving tasks and 4 th eir cr1t1cal1ty, Instructional objectives derived from that task analysis and the methods used to derive the task analysis and Instruc­ tional objectives.50 Organization The HumRRo task analysis was designed to provide driver educa­ tors, researchers and other professionals with a set of technical data. These data were designed to: "provide a detailed description of the behaviors required of drivers of four-wheeled passenger cars together 51 with the rated cr1t1cal1t1es of these behaviors." They were developed to help provide a description of good driving to further the development of sound driver education programs. The specific purpose 50 A. J. McKnight, Driver Education Task Analysis, Volume I : Task Descriptions (Springfield, Virginia: National Technical Informa­ tion Service, 1970), p. v11. 51 A. d. McKnight, Driver Education Task Analysis, Volume I I : Task Analysis Methods (Springfield, Virginia: National Technical Information Service, 1970), p. v. 27 fo r this task analysis was stated as: "to Id e n tify a set of driver performances that might be employed as terminal objectives 1n the 52 development of d river education courses." I t was also f e l t that they would "provide a broad foundation fo r further Inquiry Into the 53 nature o f d riv e r's resp o n sib ility." This document, then, was seen as being of use to d river license, law enforcement, and other pro­ fessionals Involved 1n t r a f f ic safety. The task analysis was prepared 1n four volumes. Volume I Included the driving tasks, divided Into the categories o f road behaviors, off-road behaviors, tasks related to the environment and a bibliography. Volume I I described the method used to analyze the driving tasks and evaluate the c r itic a l1 ty of d river behaviors. Preparation o f the task descriptors, behavlorally relevant system ch aracteristics, directions to evaluators of cr1t1ca!1ty, task c r i t i ­ cal It y , means and standard deviations, and a 11st of evaluators were presented. Part 1 o f Volume I I I lis te d the Instructional and enabling objectives, grouped into 74 learning u n its, as developed from the task analysis. Evaluation instruments fo r driving fundamentals, driving s k ills and driving knowledge were found In the second part of Volume III. Volume IV described the manner In which the Instructional objectives, enabling objectives, driving fundamentals te s t, driving 54 s k ills te s t and knowledge te s t were formulated. 52McKn1ght, Volume I , p. v11. 53Ib1d. ^McKnight, Volume IV , p. 111. 28 Construction o f Task Analysis The HumRRo Task Analysis was to provide a d e fin itio n o f what was good driving. In order to provide a d e fin itio n o f good driving an analysis o f the System's goals was required. defined as: The system goals were "Assuring the movement o f passengers and material from one place to another with safety, e ffic ie n c y , comfort and responsl55 b lU ty ." Each of these system goals then provided Its own set of behavioral requirements to achieve good driving. A lite ra tu re review was undertaken to obtain behavioral characteristics to include 1n a task analysis. The review Included 600 Items from "textbooks, research reports, technical reports, accl56 dent s ta tis tic s , le g is la tiv e documents and film s." A systematic task analysis was then conducted on the Informa­ tion gathered by the lite ra tu re review to find Information that would be relevant to meeting the driving goals as defined by the system goal. A 11st of 1,000 characteristics o f the transportation system 57 were generated o rig in a lly 1n th is manner. The 11st of 1,000 characteristics was combined Into a 11st of Interacting characteristics which had relevance to the system goals. This became a 11st o f 1,700 tasks, divided Into 45 areas required In good d riv in g .58 55McKn1ght, Volume I I , p. 7. 56Ib1d., p. 6. 58McKn1ght, Volume IV . p. 4. 57Ib 1 d ., p. 9. 29 The l i s t was organized Into two areas: tasks. on- and off-road Tasks were lis te d once with cross references fo r those appear­ ing In more than one behavior required fo r good driving. The tasks were then ranked fo r c r it ic a lIt y 1n fiv e categories from high c r lt lc a lit y to low cr1t1cal1ty. This ranking was performed 59 by 100 authorities In a ll areas of t r a f f ic safety. R e lia b ility There were two forms o f r e lia b ilit y obtained fo r the HumRRo task analysis: Inter-judge r e lia b ilit y for use between groups o f tasks; and Inter-judge r e lia b ilit y fo r use w ithin groups of tasks. Both measures showed a high level o f agreement on an analysis o f variance technique* .82 and .99+ respectively.60 tasks a t each level o f c r itic a l1 ty . Objectives were w ritten for The objectives were grouped Into 74 learning units with a statement o f purpose, l i s t of performance objectives, description o f enabling s k ills , and knowledge o bjectives.6^ Other Users o f HumRRo I t would be Impractical to report a ll of the studies which have used the HumRRo task analysis since Its completion 1n 1971. This sec­ tion w i l l , therefore, specify fiv e major studies which used the HumRRo task analysis. This w ill serve to Illu s tr a te Its acceptance as a comprehensive source authority fo r driving tasks. I t w ill also make the case fo r the use o f the HumRRo task analysis 1n this study. 60McKn1ght, Volume I I , p. 19. 61McKnight, Volume IV , p. 19. 29 The 11st was organized Into two areas: tasks. on- and off-road Tasks were lis te d once with cross references fo r those appear­ ing 1n more than one behavior required fo r good driving. The tasks were then ranked fo r c r lt lc a llt y 1n fiv e categories from high c r itic a l1 ty to low c r l t l c a l lt y . This ranking was performed 59 by 100 authorities in a ll areas o f t r a f f ic safety. R e lia b ility There were two forms of r e lia b ilit y obtained fo r the HumRRo task analysis: Inter-judge r e lia b ilit y fo r use between groups of tasks; and Inter-judge r e lia b ilit y fo r use within groups of tasks. Both measures showed a high level of agreement on an analysis of variance technique, .82 and .99+ respectively.®0 tasks at each level of c r lt lc a llt y . Objectives were w ritten fo r The objectives were grouped Into 74 learning units with a statement o f purpose, 11st of performance objectives, description o f enabling s k ills , and knowledge objectives.6* Other Users o f HumRRo I t would be impractical to report a ll of the studies which have used the HumRRo task analysis since Its completion In 1971. This sec­ tion w i l l , therefore, specify fiv e major studies which used the HumRRo task analysis. This w ill serve to illu s tr a te Its acceptance as a comprehensive source authority fo r driving tasks. I t w ill also make the case fo r the use o f the HumRRo task analysis in th is study. 60McKnight, Volume I I , p. 19. 6 lMcKn1ght, Volume IV , p. 19. 31 performance curriculum from instructional objectives developed In a previous part of the project. 66 The National Public Services Research In stitu te (NPSR1), used the HumRRo task analysis to develop Driver Manuals for drivers age 55 and older for the state of Virginia. From 1t they developed a 20- item, 3-frame test which identified most c ritic a l tasks. With this they tested 8,000 drivers aged 60 and older to gain Information for 67 Inclusion In their driver manual. The f if t h user of the HumRRo study was the Highway Safety Research In stitu te at the University of Michigan. They developed the National Item Bank fo r Tests of Driving Knowledge based upon the tasks identified in the HumRRo study. They saw the HumRRo task analysis as a complete, well supported document. The degree of c r ltlc a llt y to the driving task made I t an excellent taxonomy of behaviors and knowledges from which to draw th eir Items for test construction. 68 They used the very and most c ritic a l behaviors to construct th e ir Item pool.®® Five major driver and tr a ffic safety education studies have recognized the HumRRo task analysis as a good product. 66 Their research U.S. Department of Transportation, op. c 1 t., p. 57. ®^A. J. McKnight and M. Green, Safe Driver Knowledge Dissemi­ nation and Testing Techniques. Final Report, Volume 2 (Springfield, Virginia: National ^Technical Information Service, 1977), p. 20. 68W. T. Pollock and T. L. McDole, Development of a National Item Bank fo r Tests of Driving Knowledge: Final Technical Report (Ann Arbor: Highway Safety Research In s titu te , 1973), p. 12. 69Ib 1 d ., p. 20. 32 efforts have been based on the HumRRo task analysis. They have accepted the HumRRo task analysis as "the most Inclusive description to date of the cognitive and behavioral elements of passenger car d riving."70 Relevance of the HumRRo Study The HumRRo task analysis was related to this study 1n three Important ways. The f ir s t was that the HumRRo task analysis represented the f ir s t comprehensive approach to defining the driving task. These task descriptions served as a comprehensive source of authority of driver knowledge. The task descriptors were the "framework on which to 71 build the passenger car driver license Item pool." The special test set (STS), based on this comprehensive task analysis, could Inventory a given population for driver knowledge deficiencies. The HumRRo study provided a c r ltlc a llty rating fo r each task description 1n the study. This was valuable to this research because "only the Items with a 4+ or higher c r ltlc a llty were used to construct 72 the Item pool." The task descriptors gave "detailed descriptions of the behaviors required of a ll drivers of 4 wheeled passenger cars, 73 together with the rated crit1ca!1t1es of these behaviors." In this 70Pollock and McDole, Item Bank, p. 12. 7^McKn1ght, Volume I I , p. 3. 72Ib1d., p. 20. 73McKn1ght, Volume I . p. v11. 33 manner the STS derived from these c ritic a l tasks descriptors was a test of c r itic a l driver knowledge. The third reason fo r the importance o f the HumRRo study was that each question 1n the STS could be tied d irectly to the c ritic a l objective In the HumRRo study. A report of deficient c ritic a l driver knowledge could be tied d irec tly to the c ritic a l HumRRo objective the STS question was designed to represent. The a b ility to Identify objectives for each deficient knowledge area made this study a valu­ able tool to educators and curriculum personnel. The HumRRo task analysis allowed this organized approach to defining what c ritic a l driver knowledge was lacking 1n the senior driver population, and relating that Information to well-defined Instructional objectives. Summary The HumRRo task analysis has served as the base for many major tr a ffic safety related research projects. I t provided a com­ prehensive task description o f the total driving task with rated c r ltlc a lltle s from which the test Instrument for this study was drawn, the Special Test Set. The HumRRo task analysis provided a framework of Instructional objectives tied d irectly to the Special Test Set Items with which to analyze the results of testing. The HumRRo task analysis allowed for this Inventory of c r itic a l driver knowledge and provided Instructional objectives to help analyze the data from the knowledge inventory. The next section w ill report on the Highway Safety Research In s titu te (HSRI) Item pool and special te s t set. 34 HSRI Item Pool This section defines the Highway Safety Research Institu te (HSRI) Item Pool (IP ), and the Special Test Set (STS). I t describes the construction and Item evaluation a c tiv itie s fo r the IP and STS. I t lis ts other users and Indicates how the IP and STS were central to the completion o f this research. Defined Two documents were considered In this section of the review of the lite ra tu re . They were the STS and IP, two parts of the Handbook fo r Driving Knowledge Testing. Item pool. The IP 1s a collection of 1,313 multiple-choice driving knowledge test development m aterials.7^ The IP questions were w ritten for those tasks with a very or most c ritic a l rating 75 • 1n the HumRRo task analysis. Special test set. Due to practical considerations 1t was necessary to collect validation and normative data on something less than a ll 1,313 questions 1n the Item pool.76 A representative group of 246 multiple-choice Items that "reflect Items with high 77 c r ltlc a llt y to safe, e ffic ie n t driving" were selected from the item pool to be the STS. 74Pollock and HcDole, Item Bank, p. 1. 75Ib1d., p. 20. 77Ib 1 d ., p. 51. 76Ib1d., p. 49. 35 Construction of the Item Pool and Special Test Set The IP was constructed as a primary document consisting of 1,313 test items. The STS was developed from the IP as a more manageable test item document from which to gather psychometric and normative data. This section describes the construction of the class "C—passenger cars and lig h t trucks" item pool and the sub78 sequent construction of the STS. Item pool construction. The class "C" Items were reported In the Handbook for Driving Knowledge Testing. The IP was designed to be a massive collection of facts, written as questions, about 79 safe, e ffic ie n t, legal driving. Three categories of driving facts were established. They were: driving principles, driving laws and t r a f f ic control 80 procedures. A comprehensive source of facts was found for each of the above categories. The HumRRo task analysis was selected 81 as the driving domain for the driving principles category. The large size (1,500 Items) of the HumRRo task analysis caused items 82 to be written for only the very and most c ritic a l tasks. 78Ib id ., p. 4. 79W. T. Pollock and T. L. McDole, Handbook for Driving Knowledge Testing (Ann Arbor: Highway Safety Research In s titu te , TdWy, p . 'T 80Ib1d. 82Ib id . 81 Ib id ., p. 5. 36 Information from the task analysis was supplemented by facts taken from state licensing tests and an extensive review of the lite ra tu re . The Uniform Vehicle Code, 1968 Edition, served as the re fer84 ence for the driving laws section. The Manual on Uniform T ra ffic Control Devices, 1970 Edition, was the source document for facts in the tr a ffic control procedures category. 85 A uniform format was followed to w rite items for the Item pool. 86 The rules for easy readability in Item construction were as follows: 1. Keep the Item's stem less than seventeen words. 2. Keep the answer choices, also called " fo ils ", to a minimum, uniform number of words in a given Item. 3. Use one-syllable, rather than poly-syllable words, when possible. 4. Use common expressions when possible rather than tech­ nical terms, e .g ., "speed up" rather than "accelerate". Avoid technical jargon and regional terms.87 A multiple choice format was selected for the item pool questions for the following reasons: 1. Most of our source document statements were restatable as multiple-choice items. 2. Most state licensing tests presently use a m ultiplechoice Item format. 3. This format is compatible with most automatic testing procedures. 83Ib1d. 84Ibid. 85Ibid. 86Ib1d., p. 6. 87 Pollock and McDole, Item Bank, p. 26. 83 37 4. Items so prepared are easily convertible to fewerchoice or true-false formats. 5. By judicious selection of answer alternatives, a considerable amount of Information can be presented and tested 1n a single multiple-choice Item. 6. A standardized Item format permits use of any set of Items 1n a test battery without test-taker confusion over several sets of instructions. 7. Multiple-choice Items are easily scored, with the results suitable for a variety of sta tis tica l tre a t­ ments. 88 None of the 12,000 test Items reviewed could meet the uni­ form format requirement.®® written. A total of 1,313 unique test Items were The major headings were broken down as follows: Driving Principles Pre-Operative Procedures Basic Knowledge Driving Situations Vehicle Situations Driver Repons1b1l1t1es 25 427 202 62 7 = 723 Vehicle Code: Laws and Regulations 339 T raffic Control Signs, Signals 251 and Markings 1,313 Items items Items Items Items Items Items Items Items^O The item pool consisted of 1,313 Items that covered the c ritic a l tasks of driving principles, tr a ffic laws and tr a ffic control devices. Special Test Set construction. This section describes con structlon of the 246-1tem Special Test Set. DO Pollock and McDole, Handbook, p. 6. 89 Ib id ., p. 7. 38 The fu ll Item pool of 1,313 Items was too large to be prac01 tlc a l for use In the "real w o r l d . A sample of the fu ll pool of Items was developed to allow fo r easier collection of normative and ftp validation data. This sample set of Items was called the Special 93 Test Set of Items (STS). Full pool Iowa data allowed an Item cluster analysis to be used to find sets of four or more Items that 94 showed high 1nter-correlat1on. Item cluster data were used 1n combination with an Item d iffic u lty Index to select Individual Items 95 for STS. R e lia b ility data, also from the Iowa p ilo t study, were then used to "maximize the Inclusion of reliable Items In the STS."®® A fin al check on the STS consisted of a comparison to the taxonomy to: determine respresentatlveness of the fu ll pool knowledge domain, and to determine that Items re fle c t high c r i t i ­ cal 1ty to safe, e ffic ie n t driving were included 1n the STS.97 9 lIb1d., p. 12. 92 Pollock and McDole, Item Bank, p. 50. 9^Pollock and McDole, Handbook, p. 12. 94 Pollock and McDole, Item Bank, p. 51. 95Ib1d. 97Ib1d. 96Ib1d. 39 The STS broke into major headings as follows: Driving Principles Pre-Operative procedures Basic Knowledge Driving Situations Vehicle and Driver Driver Responsibilities 1item 99 items 34 Items 13 items 2 items 149 1terns 58 Items Vehicle Code: Laws and Regulations T ra ffic Control Signs, Signals and Markings 39 items TOTAL 246 "!tems98 The STS represented a scaled-down version o f the IP. I t was constructed from the IP and used cluster analysis, d iffic u lty indices, r e lia b ilit y data and taxonomy check to establish i t as representative of the IP. The STS compared favorably with the IP on the four measures described above. Item Evaluation A ctivities Construction of the class "C" Item pool completed phase I of the Item Bank project. evaluation a c tiv ity . Phase I I consisted o f three stages of Item The Item pool was evaluated on its language adequacy, content v a lid ity and psychometric characteristics. Phase I I I reported the STS evaluation a c tiv itie s . Language adequacy. measures. Language adequacy was evaluated on two The f i r s t measure of language adequacy was a Flesch count of reading ease. The Flesch count showed a 7th grade reading level 99 for the item pool. The second measure of language adequacy was 98Ibid. "p o llo ck and McDole, Handbook, p. 8, 40 a language review by nine local (Ann Arbor) high school students.*0® The language review for unclear items resulted in modification of over half of the item pool.*0* Content v a lid ity . Content v a lid ity was checked by using "64 primary authorities," some of which participated in the HumRRo study, to compare HumRRo task statements to th eir corresponding item pool questions. 102 Over half of the items were modified to remove ambiguity and inaccuracy a fte r review by the authorities. Psychometric evaluation. 103 Psychometric data were collected on measures o f Item d iffic u lty , item r e lia b ility and item correla­ tion to unrelated variables. Item d iffic u lty was "expressed as the proportion of respon­ dents correctly answering the item ."*0^ Any item with an Item d iffic u lty of .50 or less was rewritten. 105 Item r e lia b ility was "expressed as the correlation between responses in a test-retest s itu atio n ."*00 A test-retest coefficient of less than .30 resulted in rewriting of the question.*07 *00Pollock and McDole, Item Bank, p. 33. 101 Ib id ., p. 35. * 02Ib1d., p. 36. * 03Pollock and McDole, Handbook, p. 10. 104Ibid, * 05Ib id ., p. 11. *06Ib id ., p. 10. *07Ib1d., p. 11. 41 Item correlation to unrelated variables was expressed as "a correlation with verbal a b ility scores.' ino Verbal a b ility corre­ lations of .30 or more resulted in the revision of an item .100 The psychometric analysis caused nearly 500 items to be rew ritten .1* 0 The rewritten items went through the Iowa test-retest procedure. Test-retest correlation, verbal a b ility correlation and p-value data were reported for each of the 1,313 items in the Hand­ book for Driving Knowledge Testing. Special Test Set evaluation. from the IP. The STS Items were selected All data reported for the IP were also reported in the same volume for the STS items. The STS was chosen to serve as a practical vehicle with which to collect item normative data on a representative sample of questions from the IP. Item normative data for the 246 Item STS were collected on 227 Cape May Coast Guard re c ru its .111 Item normative data were also collected on 2,940 Michigan original license applicants, 34,251 Michigan renewal license applicants, 1,090 problem drivers and 511 transfer license applicants. 112 Item normative data were reported for the STS items 1n the Handbook for Driving Knowledge Testing for a ll classes of Michigan and Cape May drivers. 108 Ib id ., p. 10. 109 I b i d . , p. 11. 110 Ibid. 111 112 I b i d . , p. 13. I b i d . , p. 12. 42 Other Users of the HSRI Item Pool The HSRI Item Pool Is not a s ta tic document. Other users o f the IP found 1t a valuable document for th eir research because of the extensive analysis and normative data on Its Items, four recent projects Identified as using the IP that are b rie fly reported 1n this section are: the California Department of Motor Vehicles Study; the Iowa PRIDE Project; the Mesa, Arizona project; and the University o f Michigan Driver License Project. California department of motor vehicles study. A 1975 study by the California Department of Motor Vehicles compared the IP to the Department's present test. This project was designed to find the best test to use to predict future driving performance. They tested 48,000 driver license applicants and found the IP more related to biographical data (educational level) than was the Department's test. 113 Neither test was found to be more or less related to 114 driving records. They chose the IP as a comparison document 115 because "1t was based on a task analysis of the driving task." Iowa project PRIDE. Another user of the IP was the State of Iowa 1n Its 1975 project, Program Research 1n Driver Education. PRIDE. They wanted to develop a test with Items that would allow fo r driver education course comparisons across many programs as well as test for 1130. W. Carpenter, An Abstract of an Evaluation of the C ali­ fornia Driver Knowledge Test and the University o f Michigan Item Pool (Sacremento: State of C alifornia, Department o f Motor Vehicles, 1975), p. 1. l l 4 Ib1d. l l 5 Ib 1 d ., p. 3. 43 safe and e ffic ie n t d riv in g .118 They chose the IP because Its re la ­ tionship to the HumRRo task analysis made the Items "appropriate."117 They p ilo t tested 2*500 Iowa d river education students 1n the development of th e ir fin a l 50 Item te s t. Mesa pro.lect. 118 The Mesa, Arizona, Public Schools used the IP to pre- and post-test 4,500 d river education students. This project was designed to f a c ilit a t e program Improvement and develop a system 119 of matrix testing fo r d river education 1n th e ir school system. The IP was chosen as a source document because of Its "te s t-re te s t and 120 verbal a b ilit y correlations, and response d istrib u tio n s." Driver license p roject. The IP was used by the University of Michigan's Highway Safety Research In s titu te In a jo in t contract with the Michigan Secretary o f State's O ffice. .They p ilo t tested the STS on 3,451 Michigan drivers in four groups: original applicant, 121 transfer appHcanti renewal and driver Improvement. The STS was divided into seven equivalent content forms of 40 Items each. 116L. R. Tack, Iowa Driver Education Evaluation Study: Final Report, Program Research In Driver Education, PRIDE (Des Moines: Iowa Department o f Public Instruction, 1975), p. 131. l l 7 Ib1d. l l 8 Ib1d. 119 R. J. Dempster, An Analysis of Driver Knowledge Test Results fo r School Year 1974-75: Technical Memorandum (Mesa, Art zona: K-12 Highway Safety Education Project, 1975}• p. Z. l2 0 Ib1d., p. 1. 121W. T. Pollock and T. L. McDole, Development of a National Item Bank fo r Tests o f Driving Knowledge: Final Technical ReporT (Ann Arbor: Highway Safety Research In s titu te , 1973), p. 63. 44 The seven forms were then balanced with Iowa psychometric data to obtain equal content d iffic u lty levels. 122 The forms fo r the renewal examinations were reduced Into 28 tests o f 10 Items each that represented a "reasonable" balance o f content and d iffic u lty le v e l. 123 The results of the p ilo t tes t led to HSRI receiving a contract to develop new original applicant and renewal license examinations for the State of Michigan based on the STS. Relevance o f HSRI Item Pool and Special Test Set The IP and Its STS were the basic documents fo r this study. They were constructed from the task analysis, Uniform Vehicle Code, and Manual on Uniform T ra ffic Control Devices which are respected, well recognized source documents fo r t r a f f ic facts. Item construc­ tion followed uniform rules which were rigorously applied. questions of analysis. The the IP and STS were representative of theHumRRo task The STS provided a group o f Items that tested very and most c r itic a l driving knowledge. The STS items presented analysis and normative data that were accepted fo r use 1n other research projects. The STS was chosen as the source document fo r Items to te s t C ritic a l Driver Knowledge 1n th is project. l2 2 Ib1d., p. 57. l23Ib1d., p. 58. 124Statement by T. L. McDole, telephone conversation, March 28, 1978. 45 Summary The STS provided well constructed Items for use In a compre­ hensive test of c ritic a l driver knowledge. Results of the testing were not confounded for reasons of unclear language, a level of language that was too d if f ic u lt, Improper correlations with verbal a b ility , too l i t t l e or too much Item d iffic u lty , or low tes t-re test r e lia b ilit y . The STS was used fo r federally funded research projects 1n C alifornia, Arizona, Michigan and Iowa. The STS was a complete Item source authority that provided a good measure of c ritic a l driver knowledge. Summary This chapter presented a review o f the lite ra tu re dealing with an Inventory of c ritic a l driver knowledge for senior drivers. The senior driver has experienced driving d iffic u lty due to a number of Interrelated medical, a ttltu d ln a l, cognitive and neuromuscular problems. I t was shown that senior drivers are ex­ pected to Increase In number and proportion for the next twenty years. Their driving problems are expected to be f e lt with great effect 1n the future. Lack of driving knowledge was Indicated as a major d iffic u lty for senior drivers; but l i t t l e agreement was found on the level or types of driver knowledge found lacking In senior drivers. The HumRRo study provided a comprehensive framework of driving tasks called the task analysis. The task analysis Identified the necessary tasks for safe, e ffic ie n t driving of the automobile. Each 46 identified task was rated for c r itic a lIty . The results of the HumRRo task analysis were widely accepted and used 1n other research. Due to its completeness and rated c r itic a litie s the task analysis was the basic document used in the construction of the item pool The Item pool provided 1,313 questions about driving know­ ledge. The item pool was written on the very and most c ritic a l driving tasks identified by the HumRRo task analysis study. The Item pool provided v a lid ity , r e lia b ility , and psychometric and normative data for test questions. The items 1n the special test set were a representative sam­ pling of questions from the item pool. Both the item pool and the special test set were used 1n research and curriculum development projects. The questions of the special test set contained the same data as the questions from the Item pool. The special test set Items had additional Information In the form of normative data which allowed comparisons of responses to other sim ilar populations. The special test set was found to be a respected, well constructed, often used Instrument for data collection. The special test set was the best instrument to use to obtain a good measure of c ritic a l driver know­ ledge 1n the senior driver population. The next chapter w ill describe the population and sample selection. Chapter I I I w ill also describe the design, methodology and Instrument used to complete the study. CHAPTER I I I DESIGN AND METHODOLOGY This chapter outlines the design and methodology used In the study. Topics described 1n detail are: selection of the population; selection of the sample; the variables of Interest; measurement of the variables; data collection; description of the test Instrument; and organization of the data and findings that were relevant to the study. Population Selection The population fo r this study consisted of a ll motor vehicle operators listed In the Michigan Department of State driver license f i l e who were born before January 1, 1913 and resided 1n Ingham County. The senior driver population of Ingham County was chosen because the driving locations of Ingham County represented a good cross section o f most driving situations 1n Michigan. This was due to the fact that Ingham County Included the metropolitan area of Lans1ng/East Lansing where c ity streets, urban residential, urban freeway, and urban Interstate highway environments were found. Mason, W111lamston, Leslie, Stockbrldge, Dansvllle and Webbervllle provided small town street, rural state and county trunkHne and and rural Interstate driving situations. Suburbs such as Haslett, Holt and Okemos included typical suburban street and highway 47 48 situations. The townships provided rural trunkHne and In terstate driving experiences. Ingham County provided drivers with many driving experiences which were lik e ly to be sim ilar to other areas of Michigan. Sample Selection The sample frame for th is study was 1,134 drivers randomly selected from the estimated 15,802 senior drivers residing 1n Ingham County, Michigan. The 15,802 senior d river records were stored with those of a ll other licensed drivers on 40 tapes at the Michigan Department o f State. Tapes 1, 14, 25 and 34 were selected by using 2 four consecutive numbers from a random number 11st. A ll driver records fo r persons age 65 and o lder, residing 1n Ingham County, were printed as the sample frame fo r th is study. Each o f the 1,134 selected drivers had the same chance o f being selected as any of the remaining 14,633 Ingham County senior drivers. Past studies by the Department of State have shown th at the numerical/alphabetical ordering of names on the computer tapes did not Introduce any known perio dicity 1n th e ir measured resu lts. I t was also found that composite performance o f drivers on one tape 1s the same as composite ^J. A. Hayes, Michigan Driver S ta tis tic s , #10 (Lansing: Department of State, 197?), pp. 23-2$. 2 G. V. Glass and J. C. Stanley, S ta tis tic a l Methods in Education_and Psychology (Englewood CUfTsi Prentice h a ll, In c ., 1970), p. 510. 49 Q performance on any other tape. ' A Bloomfield used the same sampling procedure 1n his study o f senior drivers and mentioned that: there was no reason to believe that the driving perfor­ mances or the proportion o f senior drivers was any d iffe re n t for the sample computer reel selection or any other reel which might have been randomly selected.5 The 1,134 senior driver records were then s tr a tifie d on the basis o f sex (male and female) and two-year accident history (none— one or more). A random selection process, where subjects' names were selected from an urn, was conducted to f i l l each sub-cell in the design. The random selection process was continued u ntil 52 senior drivers were selected to receive form A, B, and C of the driver knowledge Inventory. The actual sample ce lls appeared 1n a two-by-two design. The knowledge inventory o f 246 items was too large to be given to one person. Thus, the knowledge Inventory was divided into three equivalent forms. Forms A, B, and C. Within each cell a set of three randomly selected sub-cells with equal size was created. Each sub­ cell was designated to receive a d iffe re n t form of the knowledge Inventory. The combination of three persons, one 1n each sub-cell, receiving one form of the 82-1tem knowledge Inventory was the same 3 Statement by Mr. J. Lucia, Michigan Department of State, personal Interview, January 20, 1978. 4 Statement by Mr. J. A. Hayes, Michigan Department of State, personal Interview, January 20, 1978. 5 6. J. Bloomfield, "A Descriptive Study o f Senior Driver Accident Records in the State of Michigan by Age Group, Sex, Urban and Rural Residency" (Ph. D. dissertation, Michigan State Univer­ s ity , 1971), p. 37. 50 as 1f one subject 1n each c e ll received a fu ll knowledge Inventory of 246 Items. The Tukey bridge argument allowed for collapsing sub­ c e ll means Into cell means when assumptions of equal ce ll size and C random selection were met. The logic o f the argument held fo r the study because o f equal c e ll sizes and random selection for sub-cells. The results represented a random estimation of the population from which they were selected. According to the study design, a sample size of 52 subjects would necessitate Interviewing, or contacting, 156 senior drivers. In order to maintain equal cell and sub-cell sizes, the next possible sample size would increase to 56 subjects. tated an additional 12 contacts. That would have necessi­ Since Interviews, Including travel time, were estimated to take two or more hours each, a maximum prac­ tic a l number was set at a sample size of 52 subjects, or 156 contacts. Study Variables Dependent Variable The dependent variable fo r the study was c r itic a l driver knowledge. Deficient c r itic a l driver knowledge was hypothesized as not being equal to 80 percent correct. Hq : S.D. y ■ 80 H-j: S.D. v t 80 Cornfield and J. Tukey, "Average Values of Mean Squares and F actorials," The Annuals of Mathematical S ta tis tic s , vol. 27, no. 4 (December 1956), p. 90$. 51 C ritic a l driver knowledge as a measure o f the variance be­ tween group means was hypothesized as being equal, or no variance. Group means tested with a 2-way ANOVA using the following three hypotheses: 1. The main e ffe c t o f sex was tested by answering the following question: Was the mean score for males and the mean score fo r females equal? HQ: y M “ y F Wy y M t y F 2. The main e ffe c t o f accidents was tested by answering the following question: or moreaccidents Was the mean score fo r seniordrivers 1n the past two years equal to the with one mean score fo r senior drivers with no accidents 1n the past two years? HQ: y ACC ** y No ACC H^: y ACC t y No Acc 3. The 2-way Interaction e ffe c t between sex and accidents was tested by answering the following question: Were the mean scores fo r females with no accidents In the past two years, females with one or more accidents 1n the past two years, males with noaccidents In the past two years,and males with one or moreaccidents past two years equal? H„: n F„ * u Fy ‘ p Hn ' “ Hy H,: ii Fn t n Fy f u Mn t m My 1n the 52 Independent Variables Sex was an Independent variable In th is study. I t was report* ed as male or female from the notation on the driver records obtained from the Department of State. Accident history was the second Independent variable. The accident history o f an Individual was reported from his d river record as "no" or "one or more" accidents during the past two years. Acci­ dents considered 1n th is study occurred 1n the time period from March 1, 1976 u n til April 13, 1978. This allowed a 45 day time period fo r posting accident records on the Department o f State's driver 7 license f ile s . This two year plus 45 day time period allowed fo r the study of a two year accident history fo r each d river that was not confounded by system delays 1n posting accident reports. was made to allow fo r fa u lt 1n any given accident. No attempt The drivers were lis te d as eith er "1n" or "not 1n" an accident In the past two years. Measurement o f the Variables The data were collected on the test form. Data were trans­ ferred by the w rite r to mark-sense sheets fo r use 1n the Item analysis program. The item analysis was programmed to punch Individual data cards from each mark-sense sheet fo r use 1n the analysis of variance program. Statement by Ms. J. Pixley, Michigan Department o f State, personal interview , A pril 10, 1978. 53 Dependent Variable C ritical driver knowledge was measured by two methods. The f i r s t method of measuring c ritic a l driver knowledge was by reporting a frequency count that was rank ordered from the most to the least missed Item. An Item analysis was done on the data to determine the frequency and performance of the test Items. The frequencies o f each of the 246 Items were determined by Item d iffic u lty . Item d iffic u lty was defined as the proportion of the total group who marked an Item o Incorrectly. The items were rank ordered and displayed (see Appendix A) from most to least missed. In the Item analysis data. Item discrimination was also Included Item discrimination Is "the difference between the proportion of the upper group who got an Item right and g the proportion of the lower group who got the Item rig h t." An Item with a discrimination value of 0.0 or less was flagged as a possibly defective Item with ambiguities, hidden clues or other technical problems.10 The Item discrimination data were displayed 1n a table. Individual test scores were summarized and presented by group and percent correct. The total test mean score was computed and a "t" tes t was performed on that mean. The "t" test compared the total tes t mean with the hypothesized level of 80 percent correct. sity: ®The Scoring O ffice, "Item Analysis" (Michigan State Univer­ Learning and Evaluation Service, 1977), p. 2., (mimeographed). 9Ib1d. 10N. Gronlund, Measurement and Evaluation 1n Teaching, Third Edition (New York: MacMillan, 19/6), p. 27$. 54 A "t" test was used because the populations1variation was unknown and had to be estimated from the sample's standard deviation. Since 80 percent correct was used 1n a recent Michigan driver education study,^ and "the criterion level or cutting score 1s generally set subjectively on the basis of judgment or experience," 12 1t was considered an appropriate level for the study. The second method of measuring c ritic a l driver knowledge was the reporting and comparing of group scores for each of the four groups 1n the study: Mn--male senior drivers with no accidents 1n the past two years; M^—male senior drivers with one or more acci­ dents in the past two years; F— female senior drivers with no acclcents 1n the past two years; F — female senior drivers with one or more accidents in the past two years. In this manner c ritic a l driver knowledge was the mean score for each group of senior drivers. group had equal cell sizes. Each Equal cell sizes allowed for making the assumptions necessary fo r using analysis of variance (ANOVA). assumptions were normality, equal variance and Independence. These When equal variance was violated, equal cell sizes s t i l l allowed ANOVA 13 to be used.' A 2-way ANOVA was used to determine equality for a ll sample mean scores. The four cells 1n this study required a 2-way ANOVA for analysis to show differences 1n multiple means without ^K . Schmitt, Michigan Driver Education Evaluation Project (Lansing: Department of Education, 1978), p. l l. R. A. Berk, "Determination of Optional Cutting Scores 1n Criterion-Referenced Measurement," Journal of Experimental Education (Winter 1976), p. 5. 13 Glass, op. c l t . , p. 369. 55 Increasing the alpha level. ANOVA was a good s ta tis tic to use be­ cause the design met the necessary assumptions for its use. level of significance was selected for the study. The .05 The 2-way ANOVA was run on the Michigan State University CDC 6500 computer, u tiliz in g the program packages from the second edition of the S tatistical Pack­ age for the Social Sciences.^ Independent Variables i Both Independent variables, sex and accident history, were recorded from subjects' driver records as obtained from the Michigan Department of State. (See Appendix B for a sample driver record.) Data Collection The collection of data for this study consisted of three d istin ct phases: in itia l contact by le tte r , telephone contact and testing. Contact Letters Five letters were of interest to the study. written to request subjects. publicity. One le tte r was Another le tte r was written to request Three le tte rs were written to obtain participation in the study. A le tte r was written to Mr. George Stevens, T raffic and Vehicle Administrator of the Michigan Department of State. This N. H. Nie, et. a l . , S tatistical Package for the Social Sciences, Second Edition (New York: McGraw-rfTll Book Company, 1975), pp. 410 and 428. 56 le tte r requested driver records to be used as subjects for this study. A total of 1,134 driver records were obtained for use 1n the study through Mr. Stevens' department. (See Appendix C for the le tte r to Mr. Stevens.) Another le tte r was written to Ms. Marlon Owen of the T r iCounty Office on Aging. This le tte r requested publicity in the Senior Forum of the State Journal. A small a rtic le was published 1n the April 28, 1978 edition of the State Journal. ^ (See Appendix D for the le tte r to Ms. Owen containing the newspaper a r tic le .) A third le tte r was written and sent to the prospective sub­ jec ts. This le tte r explained the study, requested th eir participation and assured the subjects of th eir anonymity. (See Appendix E for a copy of this subject contact le t t e r .) Two le tte rs were Included with the researcher's le tte r to prospective subjects. These le tte rs explained the Importance and value of the project and asked the prospective subjects to p a rtic i­ pate 1n the study. The le tte rs were written by Dean Armand Hunter of Lifelong Education Programs and Mr, Richard Austin, Michigan Secretary of State. (See Appendix F for the le tte r from Dean Hunter and Appendix G for the le tte r from Secretary Austin.) After the sub-cells were f ille d packets containing the contact le tte r , the le tte r from Dean Hunter and the le tte r from Secretary Austin were mailed to the prospective subjects. ^ S ta te Journal (Lansing), April 28, 1978, p. G1, Col. 4. 57 Telephone Contact Approximately fiv e days a fte r the contact le tte r was mailed, a telephone call was placed to the subjects requesting a convenient time fo r them to f i l l out the knowledge Inventory. Where no te le ­ phone was lis te d , a personal v is it was used for this purpose. Refusals were asked to provide the information on the demographic data sheet. (See Appendix H for the demographic data sheet.) Non- English speaking and non-reading senior drivers were dropped from the study. Testing Senior drivers were tested under sim ilar, but not Identical, conditions. All tests were administered in the home environment. All materials for taking the inventory were provided. A card table and folding chair were taken to the "In-home" testing sites to reduce variance. The respondents were asked not to ta lk about the test to reduce inter-respondent contamination. Instrument The test Instrument was an exact copy o f the 246-item Special Test Set (STS) found 1n the Handbook fo r Tests o f Driving Know!edgeJ 6 The STS was selected from a pool of 1,311 Items 1n the original Item bank. The original Item bank was written from, and can be tied d irec tly to, knowledge objectives from the most and very c ritic a l 16W. T. Pollock and T. L. McDole, Handbook fo r Driver Knowledge Testing (Ann Arbor: Highway Safety Research In s titu te , 1974), pp. 39-343. 58 driving tasks 1n the HumRRo task analysis.^7 The STS was compiled by using full-pool psychometric data developed with Iowa driver education students and Coast Guard recruits. The STS was further refined by using cluster analysis, Item d iffic u lty , r e lia b ility and taxonomy comparison data. Normative and validation data were then collected on the STS by use of four classifications of Michigan drivers.^8 The STS was considered to be too large 1n Its present form to be given to senior drivers. The STS was divided Into three equivalent forms, A,*B, and C. All three forms were 82 questions 1n length. Each form had Identical instructions, demographic data sheets, and were Identical In format. The STS was divided Into 28 content areas that were evenly divided across a ll three forms. The mean d iffic u lty level for Michigan Renewal Drivers on the questions 1n a ll three forms was 75.8. of the STS. The three forms were equivalent forms (See Appendix I for sample questions from Forms A, B, and C of the knowledge Inventory.) Organization of Data The data were organized 1n two patterns for analysis. Items were f i r s t rank ordered by frequency from most to least missed. The rank-ordered Items were displayed 1n Appendix A which showed re lative deficiency of c ritic a l driver knowledge. 17W. T. Pollock and T. L. McDole, Development o f a National Item Bank for Tests of Driving Knowledge: ^fnaT Technical Report (Ann Arbor: highway- Safety Research in s titu te , 1973), p. 20. l8 Ib1d., p. 56. 59 The mean score for each of the four groups was then computed and displayed in a 2x2 design. A 2-way analysis of variance was used to test for significant differences between the four group means. Summary This chapter outlined the design and methodology used in the study. Topics described in detail were: selection of the population; selection of the sample; the variables of interest; measurement of the variables; data collection; description of the test Instrument; and organization of the data and findings that were relevant to the study. The data and results obtained 1n the study are organized and displayed in tables in the next chapter. CHAPTER IV ANALYSIS OF RESULTS The preceedlng chapter described the design and methodology used 1n the study. This chapter presents the sample data, demo­ graphic data, data fo r Item d iffic u lty , Item discrimination and data for analysis of Individual and group scores. The Sample Data In this section data are presented which were obtained as a result of s tra tify in g , determining the sample size, and selecting the sample. S tra tific a tio n A total of 1,134 senior driver records were obtained from the Michigan Department of State. s tra tifie d with: The 1,134 senior drivers were 88 senior drivers In the male with accidents group; 481 senior drivers 1n the male with no accidents group; 57 senior drivers 1n the female with accidents group; and 508 senior drivers 1n the female with no accidents group. There were 569 male senior drivers and 565 female senior drivers 1n the sample frame (see Table 4 .1 ). 60 61 TABLE 4.1 . —S tra tific atio n of the Sample Frame: Accident and Male—Female. Accident—No Number Accidents Total Male Accidents No Accidents TOTAL Female 88 57 481_ 508 569 565 1,134 Determining the Sample Size The sample size was set at the maximum number of 52 subjects, or 156 contacts, by using the error term computed from a 24-subject p ilo t test of the driver knowledge Inventory. The error term computation called for a sample size of 168 subjects, or 504 contacts, as three contacts were equivalent to one subject. A fter the study was completed and the data analyzed, an ANOVA was performed to Increase the sta tis tic a l power of the 52subject sample. Table 4.2 Indicates that an "f" ra tio of 1.601 was obtained from a 1-way ANOVA performed on the mean total test scores of Forms A, B, and C. This Indicated no significant difference between the forms as an "f" ra tio o f 3.00 was needed to reject equality at the .05 level. Since the forms were equivalent 1n con­ tent and construction, and showed no difference In total mean scores, Forms A, B and C were testing the same things. This allowed fo r s ta tis tic a l purposes, the use o f each contact as an Individual 62 subject, not one-third of a subject. Therefore, a total N of 156 was used in the s ta tis tic a l analysis of the study. TABLE 4 .2 .—1-Way ANOVA Table of the Three Test Form Means. Source of Variance Form Residual Sum of Squares DF Mean Square F Significance of F 31.744 2 15.872 1.601 .205 1517.231 153 9.917 *C ritic a l value * 3.00. Sample Selection The mean, median and modal age for a ll senior drivers con­ tacted for purposes of this study are shown 1n Table 4.3. median, and modal age for: The mean, male participants was 72.5, 71.3, and 71; female participants was 71.7, 70.6 and 71; a ll participants was 72.1, 76.1 and 71; male non-participants was 73.3, 73 and 74; female non-part1c1pants was 73.2, 74 and 76; a ll non-participants was 73.3, 74.3 and (blmodal) 71 and 74; a ll persons contacted was 72.3, 73.2 and 71, respectively. A ll groups show sim ilar age divisions (see Table 4 .3 ). Table 4.4 shows that age range o f the sampled senior drivers with and without accidents 1s sim ilar. The male with accidents group had 11 drivers 1n the 65-69 age range; 14 drivers 1n the 70-74 age range; 10 drivers 1n the 75-79 age range; 3 drivers 1n the 80-84 age range; and 1 driver 1n the 85-89 age range. The female with 63 TABLE 4 .3 .—Mean, Median and Modal Ages of All Senior Drivers Contacted fo r Purposes of this Study. Age Groups Mean Median Mode Male participants 72.5 71.3 71.0 Female participants 71.7 70.6 71.0 All participants 72.1 76.1 71.0 Male non-participants 73.3 73.0 74.0 Female non-participants 73.2 74.0 76.0 All non-participants 73.3 74.3 71.0 All persons contacted 72.3 73.2 71.0 & 74.0 TABLE 4.4. —Age Range of Sampled Senior Drivers. Number Age Range Males with Accidents Females with Accidents Males no Accidents Females no Accidents 65-69 11 15 12 11 70-74 14 12 17 20 75-79 10 10 3 5 80-84 3 1 7 3 85-89 J_ JL _0 _0 39 39 39 39 TOTAL 64 accidents group had 15 drivers 1n the 65-69 age range; 12 drivers in the 70-74 age range; 10 drivers 1n the 75-79 age range; and 1 driver 1n the 80-84 age range. The male without accidents group had 12 drivers 1n the 65-69 age range; 17 drivers In the 70-74 age range; 3 drivers 1n the 75-79 age range; and 7 drivers 1n the 80-84 age range. The female without accidents group had 11 drivers 1n the 65-69 age range; 20 drivers 1n the 70-74 age range; 5 drivers 1n the 75-79 age range; and 3 drivers 1n the 80-84 age range. There were 14 senior drivers who could not be located from the address lis te d on th eir driver-records. Some were found to be in Florida, Northern Michigan, and Europe. The "not found" drivers were also dropped from the study. The totals fo r the sample frame are presented 1n Table 4.5. TABLE 4 .5 .—Distribution of Sampled and Non-Sampled Senior Drivers. Numbers Groups Total Fy Fn My Hn Sampled 39 39 39 156 Refused 10 15 12 39 3 Not found 3 3 3 5 Died 0 0 1 Non-Eng11sh speaking Not used* 0 8 0 _3 1 1 0 14 2 _4 12 27 60 60 60 60 240 TOTAL 40 1 *Subjects held 1n reserve and not contacted 1n the study. 65 Demographic Data The non-sampled drivers totaled 57. In the sample selection process 40 people did not agree to particip ate 1n th is study. Demographic data were collected from non-part1c1pants In th is study when they received a telephone call or Interview , requesting a time period for th e ir p articip atio n 1n th is study. The demographic data provided a basis fo r comparing the participants and non-part1c1pants 1n th is study. No one group seemed to have largely d iffe re n t demographic data. Table 4.6 1s a summary, o f the demographic data collected 1n th is study. Two senior drivers had died and one was a non-English speaking person. They represented less than two percent of the persons contacted who were dropped from the study. Item D iffic u lty and Discrimination Each 82-1tern form (A, B and C) was tested on 52 subjects from each o f the four groups: males with accidents; females with accidents; males without accidents; and females without accidents. An Item analysis was run a t the Michigan State University scoring o ffic e on the OpScan 100M to determine item d if f ic u lty and Item discrimination values fo r each question. The MSU scoring pattern "AL" was used to obtain an item analysis th at Included data cards fo r each subject 1n the study. Item D iffic u lty Item d if f ic u lty , defined as the proportion o f the group who answered the item and marked 1t co rrectly, ranged from a high o f 90 TABLE 4 .6 .—Summary of Demographic Data by P articipant—Nonpartlclpant and Accident—Non-accident Groups. Number Refusals with Accidents Subjects with Accidents Refusals without Accidents Subjects without Accidents 5.7 5.5 6.2 5.6 Years o f license 52.0 53.7 55.0 51.8 Miles driven per year 9,000 8,705 11,500 7,966 Male 12 39 3 39 Female 10 39 15 39 Highest grade 1n school 11.5 11.2 10.7 11.8 0 3 0 3 22 78 18 77 Always use seat b elt 3 20 1 17 Some use o f seat b elt 5 21 6 43 14 37 11 18 Demographic Data Days driven per week Received formal driving Instruction Own a vehicle Never use seat b e lt Married 9* 46 11 52 Widowed 7 27 7 21 Single 0 4 0 3 Divorced 0 1 0 2 * Six persons declined to answer th is question. 67 to a low of 2. The d istrib u tio n of Item d iffic u ltie s 1s presented 1n Appendix A. Item Discrimination Item discrimination ranged from a high o f 93 to a low of -29. Eighteen Items were found to have a discrimination value o f 0 or less. Such Items could not give a true Indication o f the level of knowledge fo r which they tes t because o f confounding variables In the Item's construction. Discrimination values were reported fo r the 156 Items 1n Appendix A. Item d if fic u lty fo r the e n tire knowledge Inventory had a mean value o f 37 and appeared to follow a normal d is trib u tio n . The mean Item discrimination value was 36.6 and appeared to be negatively skewed. Figure 1 shows the curve fo r item d iff ic u lty and Item discrim ination. The 24 most missed questions with an Item d iffic u lty above 60 were grouped Into seven categories. Vehicle control questions comprised the largest related category o f missed Items. vehicle control questions Included items on: The six skid control; stopping on snow; pulling a t r a il e r ; water on the brakes; night stopping distance; and slowing fo r obstructed Intersections. The second largest related category o f missed Items was t r a f f ic control signs and signals. The fiv e sign and signal items were questions on: school zone signs; obstruction 1n the road signs; y ie ld signs; and t r a f f ic signals. The th ird largest category contained four questions on license and vehicle re g is tratio n procedure. Three Items from 68 70 65 • • 29 Key: 00 10 20 30 40 50 60 70 80 90 100 Indicates Item d iffic u lty • • • Indicates Item discrimination Figure 1 .--D istribution o f Item D iffic u lty and Discrimination Indices. this group concerned suspended or no driver license and the remaining item dealt with vehicle registration law. The three Items on freeway driving and three Items on rig ht and l e f t turns were the next most missed categories. Two Items on dimming headlights 1n the face of on-coming tr a f fic were the sixth most missed category. drugs and alcohol was the fin a l category. One Item on Table 4.7 shows a rank ordering of the top 24 missed Items. The 246-1tem knowledge Inventory was divided Into three equivalent forms 1n the study. Forms A, B and C contained Items from 28 topical divisions of the knowledge Inventory, These 28 topical divisions represented a second manner of looking at most 69 TABLE 4 .7 .—Rank Ordering of Top 24 Missed Items with Related Content Areas. Item D if f i­ culty Item Discrim­ ination C-78 90 0 C-27 83 -29 C-38 81 15 Left ex it on freeway. A-13 77 29 Slowing vehicle fo r obstructed view at an Intersection. C-63 77 7 A-45 B- 4 73 15 On-coming car with bright lights. 67 15 Pulling a tr a ile r . C -ll 67 57 Right turns. C-15 C-53 67 0 Left turns. 67 License suspension. B-70 B-21 67 43 43 Missed ex it on freeway. C-43 65 22 21 B-15 63 -14 C-47 C-51 63 63 50 T ra ffic signal colors. 36 Vehicle registration. C-54 B-10 63 57 No driver license. 62 - 7 B-26 62 65 Water on brakes. C-42 62 50 Night stopping distances. C-55 62 36 Suspended license. B-75 62 29 T ra ffic construction sign. C-82 62 50 School zone sign. Item Number 65 Content Area Yellow lig h t on tr a f fic signal. Stopping a car on snow. Alcohol, drugs and driving. Yield signs. When to dim bright lig h ts. Left turns. Driving m ulti-lane roads. 70 missed items. A mean Item d iffic u lty was computed for each of the 28 topical divisions of the knowledge Inventory. The mean Item d iffic u lty for topical divisions ranged from 51 to 21. The fiv e topical divisions with a mean Item d iffic u lty above 45 were: r a il­ road crossings, bridges and tunnels; emergency situations and manuvers; skid control; driver license questions; and night driving. The six least missed divisions with a mean Item d iffic u lty below 25 were: vehicle equipment; vehicle care and service; highway driving; a n ti-th e ft laws; vehicle Inspection; and accidents and accident reports. Table 4.8 presents a rank ordering of the 28 topical divisions by th e ir mean Item d iffic u lty Indices. Analysis of Individual and Group Scores The 156-subject sample group of the study was divided into four groups containing 39 senior drivers each. Identified as: The groups were Mn« males with no accidents 1n the past two years; F * females with no accidents 1n the past two years; M , males with II Jr one or more accidents 1n the past two years; and F^, females with one or more accidents 1n the past two years. Sex and accident data used to group each subject were recorded from driver records obtained from the Michigan Department of State. Individual Scores The f i r s t hypothesis was that senior drivers would not show a c ritic a l driver knowledge level of 80 percent correct. A "t" test was performed on the total test mean o f 63 percent correct. The "t" 71 TABLE 4 .8 .—28 Topical Divisions of the Knowledge Inventory Rank Ordered by Their Mean Item D iffic u lty . Rank Order Mean Item D iffic u lty 1 51.00 Railroad crossings, bridges, and tunnels. 2 48.50 Emergency situations and manuvers. 3 47.25 Skid control. 4 46.62 Driver license. 5 46.50 Night driving. 6 44.50 Post-acc1dent responsibilities. 7 44.16 Vehicle registration and t i t l e . 8 43.36 Physical and emotional conditions. 9 41.86 Basic manuvers. 10 41.30 Driver perception and communication. 11 12 40.00 Urban driving. Speed control. Topic 13 38.80 37.60 14 37.30 T raffic signs, signals, and markings. 15 36.09 Freeway driving. 16 33.16 Road and weather conditions. 17 32.71 Rules o f the road. 18 32.50 Reacting to tr a ffic and emergencies 19 30.40 Fundamental control and manuvers. 20 30.25 Directional control. 21 29.00 Pre-operative procedures. 22 27.00 Financial responsibility. 23 24 24.55 Vehicle equipment. 23.00 Vehicle care and service. 25 22.33 Highway driving. 26 22.00 A n ti-th e ft laws. 27 28 21.33 Vehicle Inspection. 21.00 Accidents and accident reports. Braking and stopping. 72 test yielded a value of -16.50. than -1.96 was needed to o f significance. A value greater than+1.96 or less reject the null hypothesis at the.05 level The null hypothesis was tested and rejected. Hq * S.D . y 8 BO H j: S.D . p f 80 Deficient c ritic a l driver knowledge, a score below 80 percent correct, was shown by 131 senior drivers. Individual performance on the knowledge Inventory ranged from two high scores of 92 percent correct to a low score of 12 percent correct. Individual scores were lis te d by group and percent correct 1n Table 4.9. TABLE 4 .9 .—Individual Test Scores by Group and Percent Correct. Percent Correct Total Fy Mn My Fn 90-99 80-89 0 1 3 4 2 9 0 6 20 70-79 10 8 14 60-69 7 11 8 9 11 41 37 50-59 14 4 3 6 27 40-49 1 5 0 1 7 30-39 1 3 3 2 9 20-29 2 _1 1 _0 4 _0 9 10-19 2 _0 39 39 39 39 156 TOTAL 5 1 73 The 25 senior drivers, 16 percent, who scored 80 percent or more correct were 1nthe following four groups: six 1n group F ;threein group six in group Mn; F ; and ten ingroup M . II Jr / Group Scores A 2-way ANOVA using the Michigan State University CDC-6500 computer was performed on the four group means. Presented 1n Table 4.10 are the data from the 2-way ANOVA for hypotheses two, three and four. The second hypothesis was that the mean scores for males and females would not be equal. Hq: h H» y F Hy iJ M i1 ii F TABLE 4 .1 0 ,—2-Way ANOVA Table of the Group Means. Source of Variation Sex Accidents Accldents/Sex Residual (Error) Mean Square Sum of Squares OF 1.256 1 .641 .124 .939 .026 1 .026 .003 .960 6.564 1 6.564 .647 .422 1541.128 152 10.139 *C ritic a l value ** 3,84 F Significance of F 74 The main e ffe c t fo r sex yielded an "f" ra tio o f .124. An "f" ra tio o f 3.84 was needed to re je c t the null hypothesis at the .05 level of significance. The null hypothesis o f equal mean scores fo r males and females was not rejected. The th ird hypothesis was that the mean scores fo r senior drivers with no accidents 1n the past two years would not be equal to the mean scores fo r senior drivers with one or more accidents In the past two years. Hq: p ACC » p NO ACC H1: p ACC f p NO ACC The main e ffe c t fo r accidents yielded and "f" ra tio of .003. An "f" ra tio of 3.84 was needed to re je c t the null hypothesis at the .05 level of significance. The null hypothesis o f equal mean scores fo r senior drivers with and without accidents was not rejected. The fourth hypothesis was that the mean scores fo r: females with no accidents; females with one or more accidents In the past two years; males with no accidents; and males with one or more accidents 1n the past two years would not be equal. Hq: P Fn « p Fy * p Mn ** P My Hl ! “ Fn * » Fy * " Mn * 11 My The 2-way Interaction e ffe c t o f sex and accidents yielded an "f" ra tio of .647. An "f" ra tio o f 3.84 was needed to re je c t the null 75 hypothesis at the .05 level o f significance. equal mean scores fo r: The null hypothesis o f females with no accidents; females with one or more accidents 1n the past two years; males with no accidents; and males with one or more accidents 1n the past two years was not rejected. Summary This chapter presented an analysis of the results o f the study. The findings Included: sample data, demographic data, a rank ordering of deficient, c r itic a l d river knowledge found in senior drivers; a rank ordering of categories o f most missed Items; a rank ordering o f group means o f most missed Items; a summary o f Individual scores by group and percent; and a comparison o f the four group means on the knowledge Inventory. The following chapter contains the summary, conclusions, recommendations, recommendations fo r fu rther research and a discussion. CHAPTER V SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS Chapter IV contained the major findings of the study. This chapter contains a b rie f summary of the study; methods of procedure; findings; conclusions; recommendations; recommendations fo r further research; and a discussion. Sunroary of the Study I t was the purpose o f th is study to determine the level of d eficien t d river knowledge 1n senior drivers of Ingham County, Michi­ gan, and to discover differences between mean scores of four groups of senior drivers. I t was f e l t that these questions could best be answered by testing the following hypotheses: 1. 2. Was c r itic a l driver knowledge equal to 80 percent correct? Hq: S.D. p = 80 Hy. S.D. p / 80 Was the mean score for males and the mean score fo r females equal? HQ: p M = p F H,: p M t p F 3. Was the mean score fo r senior drivers with one or more accidents 1n the past two years equal to the mean score fo r senior drivers with no accidents 1n the past two years? 76 77 H0: u ACC = v NO ACC H j: p ACC f p NO ACC 4. Were the mean scores for: females with no accidents 1n the past two years; females with one or more accidents 1n the past two years; males with no accidents 1n the past two years; and males with one or more accidents In the past two years equal? H0: P Fn" u Fy “ p Mn * M My H ,: w Fn 1 p Fy tv Mn t M My Methods of Procedure The population which comprised the sample frame fo r the study consisted o f a ll Ingham County senior drivers on f i l e with the Michigan Department of State. A group o f four tapes were ran­ domly selected from the 40 computer tapes that contained an alphanumerical lis tin g o f a ll Michigan drivers. A to ta l o f 1,134 Ingham County senior driver records were printed from the selected tapes. The driver records were then s tra tifie d into four groups by sex and two year accident history. A to tal o f 39 subjects were randomly selected from each s tr a tifie d group to f i l l the four ce lls 1n the study. Letters and follow-up telephone c a lls were met by a 25 percent refusal rate fo r the study. An additional 17 subjects could not be located or were known to have died. A to ta l o f 156 senior drivers were tested with the knowledge Inventory. Test sessions were con­ ducted 1n the subjects' homes and lasted about one hour. were coded on mark-sense sheets fo r use 1n data analysis. The data A "t" 78 te s t of the to tal te s t mean and 2-way ANOVA were used to tes t the null hypotheses. Findings Hypothesis 1 Senior drivers would not show a c r itic a l driver knowledge level o f 80 percent correct. Ma.lor finding. Senior drivers were s ig n ific a n tly d e fic ie n t 1n c r itic a l d river knowledge. The mean score fo r senior drivers was 63 percent correct and the pre-set cutting score fo r non-defi­ cient c r itic a l d river knowledge was 80 percent correct. The d if f e r ­ ence between the means was s ig n ifica n t at the .05 le v e l. Additional Findings. Twenty-five senior drivers or 16 per­ cent of the sample were not d e fic ie n t 1n c r itic a l driver knowledge as they attained or surpassed a score o f 80 percent correct on the knowledge Inventory. The 24 most missed questions dealt with vehicle control* t r a f f ic control signs and signals, license and vehicle re g is tra tio n , freeway d rivin g , rig h t and l e f t turns, dimming headlights, and drugs and alcohol. The fiv e topical divisions o f the knowledge Inventory with the highest mean item d if f ic u lty scores were railroad crossings, bridges and tunnels, emergency situations and manuvers, skid control, d river licensing and night driving. The six topical divisions o f the knowledge inventory with the lowest mean item d if fic u lty scores were vehicle equipment, 79 vehicle care and service, general highway driving, a n ti-th e ft laws, vehicle Inspection, and accidents and accident reports. Eighteen Items in the special test set were found to have an Item discrimination value of 0.0 or less. Hypothesis 2 The mean scores for male and female senior drivers would not be equal. Major finding. There was no significant difference between scores of male and female senior drivers. Hypothesis 3 The mean scores for senior drivers with no accidents 1n the past two years would not be equal to the mean scores for senior drivers with one or more accidents In the past two years. Major finding. There was no significant difference between the mean scores o f senior drivers who had been in one or more acci­ dents and senior drivers who had not been in an accident in the past two years. Hypothesis 4 The mean scores for: females with no accidents; females with one or more accidents 1n the past two years; males with no accidents; and males with one or more accidents in the past two years would not be euqal. Major finding. The mean scores of male or female senior drivers did not depend on th e ir level of accident experience. 80 Conclusions The following are conclusions based upon the findings of the study: 1. ciency. Senior drivers have a c ritic a l driving knowledge d e fi­ The mean scores for a ll senior drivers on the knowledge Inventory was 63 percent correct. The cutting score for deficient c ritic a l driving knowledge was 80 percent correct. A "t" test of the means, 63 and 80, showed them to be significantly differen t at the .05 level. 2. Senior drivers have deficient c ritic a l driver knowledge 1n high stress areas requiring quick judgments, vehicle handling and s k illfu l manuvers. Six of the 24 most missed questions dealt with vehicle control. Three of the most missed questions dealt with freeway driving. Three of the most missed questions dealt with right and le f t turns. Two of the most missed questions dealt with dimming headlights at night. The second most missed topical division of the knowledge inventory was emergency situations and manuvers. The third most missed topical division of the knowledge Inventory was skid control. The f i f t h most missed topical division of the knowledge Inventory was night driving. 3. Senior drivers have deficient c ritic a l driver knowledge 1n the area of tr a ffic control sign and signal recognition. the 24 most missed items dealt with t r a ff ic signals. most missed Items dealt with t r a ffic control signs. Two of Three of the The most missed topical division of the knowledge Inventory was the area of 81 railroad crossings, bridges and tunnels. The fourteenth most missed topical division was t r a ff ic signs, signals and markings. 4. Senior drivers have c r itic a l driver knowledge 1n non­ stress, non-dr1v1ng situations. The six least missed topical divisions of the knowledge Inventory were vehicle equipment, vehicle care and service, a n ti-th e ft laws, vehicle Inspection, vehicle accident proce­ dures and reports, and general highway driving. 5. Twenty-five of the knowledge Inventory Items were Impro­ perly w ritten. Eighteen of the knowledge Inventory Items had an Item discrimination value of 0.0 or less. Seven of the Items had an Item d iffic u lty below ten. 6. There 1s no difference 1n c ritic a l driver knowledge be­ tween male and female senior drivers. The 2-way ANOVA for the main effe ct of sex showed an "f" value of .124. An "f" level o f 3.84 was needed to show a significant difference. 7. There is no difference 1n c r itic a l driver knowledge be­ tween senior drivers who have been or who have not been Involved 1n an accident 1n the past two years. The 2-way ANOVA fo r the main effect of accidents showed an "f" value o f .003. An "f" level of 3.84 was needed to show a significant difference. 8. Hale or female senior drivers did not show d ifferen t levels of c ritic a l driver knowledge because of th eir having or not having had an accident 1n the past two years. The 2-way ANOVA for the Interaction effect of accidents/sex showed an "f" value o f .647. An "f" level of 3.84 was needed to show a significant difference. 82 Recommendations The following are recommendations based on the findings and conclusions of the study: 1. Programs should be established to offer driver refresher classes for senior drivers. 2. Programs established for senior drivers should focus on Increasing senior drivers' awareness and understanding of tra ffic control signs and signals, and high stress, high density, high volume tr a ff ic situations. 3. When designing a driver refresher course curriculum for senior drivers, accident experience and sex need not be used to group students for d ifferen t treatments. 4. Eighteen knowledge Inventory Items of the special test set need to be checked for: hidden clues, ambiguity, unclear meanings, and Incorrect or missing responses. Recommendations for Further Research The following are recommendations for further research based upon the findings, conclusions and recommendations of the study: 1. A study should be conducted to discover what variables are related to the level of c ritic a l driver knowledge 1n senior drivers. 2. A study using the knowledge Inventory to test c ritic a l driver knowledge 1n youth and middle age drivers should be conducted and compared with the results obtained for senior drivers. 83 3. A study should be conducted of senior driver attitudes as related to the driving task. 4. A study should be conducted to measure senior driver performance 1n on-road driving situations. 5. A study should be conducted to create a measure or factor to rate senior driver exposure 1n tr a f fic . 6. A study should be conducted to devise a system that would Identify those senior drivers who are no longer f i t to operate a motor vehicle. 7. A study should be conducted to measure the speed and accuracy with which a senior driver processes Incoming Information and the point at which the processing begins to break down. Discussion Host Missed Items I t was Interesting to note that the most missed knowledge Items occurred In the areas where there was also poor beh1nd-thewheel performance by senior drivers. T ra ffic signs were missed by senior drivers both on the pencil and paper tests and 1n the on-road environment. Areas that require quick and s k illfu l judgments such as skid recovery, merging and lane changing posed a problem on the test as well as on the road. The data clearly point to a correlation between lack of knowledge and poor on-road performance by senior drivers. 84 Deficient Knowledge by Senior Drivers Senior drivers have shown a deficient level of c ritic a l driver knowledge. Knowledge Is not always the best measure of performance. I t 1s part of "good driving" but, Just because they don't perform well on a "paper and pencil" tes t doesn't mean they are not performing well 1n on-road, driving situations. Sometimes people do things correctly even though they answer I t wrong on a test paper. Testing situations often make people tense which might be causing them to have a d if fic u lt time relating th eir knowledge to questions being asked on the test Instrument. Senior drivers might also be having problems reading and understanding the "technical ja r ­ gon" so often involved 1n the fie ld of t r a ffic safety. A better way o f evaluating knowledge might be to observe senior drivers 1n a real world driving situation. The Main Effect of Accidents The main effect for accidents was no difference. "f" The obtained ratio of .003 leads the w riter to believe that accidents are tru ly chance events. Therefore I t 1s believed that an Increase 1n the usual two-year study period of accident history would s t i l l show no difference. Sample Size I t was unfortunate th at, for practical reasons, the sample could not meet the recommended size of 168. I t was interesting to note, however, that a sample size above 120 on the "f" table was rated the same as a sample o f In fin ite size. I t should also be noted 85 that the "f" ratios for main effects were very low at .124 and .003. I t 1s the opinion of the w riter that, had the sample size been In­ creased from 156 to 168, an "f" ra tio of significance at the .05 le v e l, 3.84, s t i l l would not have been achieved. I t 1s f e lt that the results of the study were not hurt by the lack of an additional 12 subjects. Negatively Worded Items Twenty items 1n the Item inventory were worded 1n a negative manner. These questions typ ica lly asked what not to do, offering three correct options and one Incorrect option. correctly one had to pick which was Incorrect. To answer an Item This caused quite a b it of hesitation and frustration 1n senior drivers. that the questions "didn't make good sense," etc. Most complained The w riter feels these questions could easily have been changed to eliminate much of the frustration and uncertainty fo r senior drivers taking license renewal tests. Senior Driver Competence While doing this study the w riter visited 156 senior drivers 1n Ingham County. There were 15-20 persons who appeared u n fit to operate a motor vehicle because of health reasons. There 1s no existing screening process to detect s e n ility , severe heart condtlon, stroke, severe a r th r itis and other d eb ilitatin g health problems. It 1s the opinion of the w riter that some sort of health screening pro­ cedure should be established to remove from the road persons who are u n fit to operate a motor vehicle. 86 Comparison of Groups The study was not designed to compare senior driver mean scores with mean scores obtained from other samples. I t was, however, of interest to note that the mean scores fo r the six groups used to validate the item pool and special test set were a ll higher than the mean score for senior drivers. That is to say that senior drivers scored lower than any of the validation or comparison groups. item d iffic u lty scores for each of the four groups were: Mean Iowa driver education students, 78; U.S. Coast Guard recruits, 73; Michigan original license applicants, 74; Michigan renewal applicants, 75; and Michigan transfer applicants, 81. The senior driver mean item d iffic u lty score of 63 was well below the lowest comparison group. Some thoughts on the reasons for these differences might be: 1. The senior driver sample was picked randomly from a ll senior drivers In Ingham County, Michigan. The subjects used 1n the validation studies were eith er driver education and driver refresher students or some class of Michigan driver license applicant. In either case the validation or comparison groups had good reason for being up-to-date on th eir c ritic a l driver knowledge. 2. Senior drivers might have considerably less c ritic a l driver knowledge than did the comparison groups. 3. Senior drivers might not have been as test-wise as the younger subjects in the comparison groups. 4. Senior drivers might have shown a higher level of test fatigue than the younger drivers in the comparison groups. 87 Suggestions for a .Follow-Up Study The study took almost as much travel time as 1t did 1n In te r­ viewing subjects. A suggestion would be to lim it a study of this kind to a geographic area below the county le v e l. An a lte rn ative suggestion would be to have some manner fo r the senior drivers to come to a central place fo r testing. A second suggestion would be to check on-road performance as well as driving knowledge. This would provide a double check on the level o f knowledge, and allow fo r making interpretations o f ju s t what the lack o f a certain type of c r itic a l driver knowledge means in terms o f safe driving performance. BIBLIOGRAPHY BIBLIOGRAPHY Books and Reports Carpenter, D. W. An Abstract of an Evaluation o f the C alifornia Driver Knowledge Test and the Unfversltv o f Michigan Item PooT. Sacramento: State o f C a lifo rn ia , 19^5. Dempster, R. J. An Analysis o f Driver Knowledge Test Results fo r School Year 1974-75: technical Memorandum. MeVa": K-12 Highway Safety Education Project, 1975. Forbes, T. W., et a l. Low Contrast and Standard Visual Acuity Under Mesoplc and Photoplc Illum ination, East Lansing Continuing Education Service, June 196B. Forbes, T. W., et a l . Research on Driver Performance Measures: Task 1. East Lansing: Highway T ra ffic Safety Center, Michigan State University, 1971. Glass, Gene V ., and Stanley, Julian C. S ta tis tic a l Methods 1n Education and Psychology. Englewood C U ffs , N .J.: Prentice H a ll, 1970. Gronlund, Norman. New York: Measurement and Evaluation 1n Teaching. Macmillan, 1976. Hayes, Joseph A. Michigan Driver S ta tis tic s #10. Department o f State, 1977. 3rd ed. Lansing: McKnlght, James A. and Green, M. Safe Driver Knowledge Dissemination and Testing Techniques, Final Weport, Vol. T T .S p r in g f ie ld , V a.: National Technical Information Service, 1977. « McKnlght, James A. Driver Education Task Analysis: Task Descrip­ tio n s. 4 voTsI S pringfield, Va.: National Technical Information Service, 1970. National Safety Council. Council, 1975. Accident Facts. 1975. Chicago: The N1e, Norman H ., et a l. S ta tis tic a l Package fo r the Soda! Sciences. 2nd ed. New YorlH McGraw-Hill, 1975. 89 90 Pastalan, Leon A., et a l. Street and Highway Environments and the Older Driver. Ann Arbor: In stitu te of* Gerontology* 1975. Ptanek, T. W., Condon, M. C., and Fowler, R. C. An Investigation of the Problems and Opinions of Aged Drivers" Chicago: National Safety Council, 1968. Pollock, W. T ., and McDole, T. L. Development of a National Item Bank for Tests of Driving Knowledge: Final Technical Report. Ann Arbor: Highway Safety Research In s titu te , 1973. Pollock, W. T ., and McDole, T. L. Handbook for Driver Knowledge Testing. Ann Arbor: Highway Safety Research In s titu te , 1974. Schmitt, Kara. Michigan Driver Education Evaluation Project. Lansing: Department of Education, 19^8. State of Michigan. Michigan Driver Statistics Report 6. Department of State, 19/3. Lansing: Tack, R. L. Iowa Driver Education Evaluation Study: Final Report Program Research in Dr1ver~Educat1on PRIDE* bes Moines: iowa Department of Public Instruction, 1975. U.S. Department of Transportation. The Driver Education Evaluation Program (DEEP) Study. Washington, D .t.: Government Printing O ffice, 1975. U.S. Department of He<h, Education and Welfare. The Aging Person: Needs and Services. Washington, D.C.: Administration on Aging, 1971. U.S. Congress. Senate. The Special Committee on Aging. The Needs of Elderly People. Hearing, 93rd Cong., 1st Sess., June 19, 1973. Washington, D.C.: Government Printing O ffice, 1973. Dissertations Bloomfield, G. J. "A Descriptive Study of Senior Driver Accident Records In the State o f Michigan by Age Group, Sex, Urban and Rural Residency." Ph.D. dissertation, Michigan State University, 1971. Crosier, James L. "The Development of Guidelines fo r a Driver Improvement Program for Residents of a Retirement Community." Ph.D. dissertation, New York University, 1972. McDonald, H. L. "Problems of a Select Group of Senior Drivers." Ph.D. dissertation, Michigan State University, 1971. 91 Periodical s/proceedings A llgaier, Earl. "Accident Involvement of Senior Drivers." Digest and Review {March 1965), pp. 17-19. T ra ffic Baker, S. P., and Spitz, W. U. "Age, Disease and the Driver." Proceedings Third Triennial Congress on Medical and Related Aspects of Motor Vehicle Accidents: International Association for Accident and T raffic Medicine (Ann Arbor: Highway Safety Research In s titu te , 1971J, pp. 37-40. Berk, Ronald A. "Determination of Optional Cutting Scores in Criterion Referenced Measurement." Journal of Experimental Education (Winter 1976), pp. 4-9. Birren, J. E. "Research on the Psychological Aspects of Aging." Geriatrics (1973), pp. 18-20. Brotman, H. B. "The Fastest Growing Minority: The Aging." Journal of Public Health (March 1971), pp. 249-252. American Brown, Amos J. "Cardiovascular Problems." Proceedings Third Triennial Congress on Medical and Related Aspects o f Motor VehicleAccidents: International Association fo r Accident antf T ra ffic Medicine (Ann Arbor: Highway Safety Research In s titu te , 1971), pp. 29-30. Cornfield, Jerome, and Tukey, John. "Average Values of Mean Squares and Factorials." The Annuals of Mathematical S tatistics (December 1956), pp. 907-949. D1Ma1o, D. J. "A Survey of SuddenUnexpected Deaths 1n Automobile Dr1vers." Proceedings Third Triennial Congress on Medical and Related Aspects of Motor Vehicle Accidents: International Association for Accident and T raffic Medicine (Ann Arbor: Highway Safety Research In s titu te , 1971), pp. 75-80. Fowles, D. G. "U.S. Population May Rise 31 to 41 M illion by the Year 2000." Aging (June-July 1975), pp. 14-17. K eller, William K. "Mental and Emotional Aspects." Proceedings National Conference on the Aging Driver, AMA, AAMVA (Morton Grove: Health and Safety Associates, 1974), pp. 31-34. Klebel, Edeltraud. "Age and Driver Fitness." Proceedings National Conference on the Aging Driver. AMA, AAMVA (Morton Grove: Health and Safety Associated, 1974), pp. 39-46. Lansing State Journal, April 28, 1978. 92 Lawton, Alfred. "The Doctor Looks at the Older Driver." Safety (October 1974), pp. 12-15, 40, 42. T raffic L1bow, L. S. "Older People's Medical and Physiological Character­ istics : Some Implications for Transportation." Proceedings of the Interdisciplinary Workshop on Transportation and Aging'IVasfrlngtbri: USGPO, T970), pp. TC-T9V------------------Mann, William A. "Problems of the Aging Driver." The Proceedings of the N.C. Symposium on Highway Safety (Chapel H ill: University of North Carolina Highway Safety Research Center, 1972), pp. 41-50. Planek, T. W., and Overend, R. B. "Profile of the Aging Driver." T ra ffic Safety (January 1973), pp. 1-3. Reader, George. "Keynote Address." Proceedings National Conference on the Aging Driver. AMA, AAMVA (Morton Grove: Health and Safety Associates, 19^4), pp. 9-12. Rodsteln, M. "Pathological and Physiological Changes 1n Older Adults: Effects on Drivers and Pedestrians." Proceedings Third Triennial Congress on Medical and Related Aspects oT Motor Vehicle Accidents: International Association for Accident and T raffic Medicine (Ann Arbor: Highway Safety Research In s titu te , 197)), pp. 56-60. Sears, K. A. "Specific Medical Considerations." Proceedings National Conference on the Aging Driver. AMA, AAMVA (Morton Grove: Health and Safety Associates, 19^4), pp. 27-28. Waller, Julian A. "Medical Limitations of the Elderly Driver." Proceedings National Conference on the Aging Driver. AMA. AAMVA (Morton Grove: Health and Safety Associates, 1974), pp. 71-84. Weygandt, James. "Role o f the Family Physician." Proceedings National Conference on the Aging Driver. AMA, AAMVA (Morton Grove: Health and Safety Associates, 1974), pp. 55-58. Weiner, Earl L. "Loss of Mobility 1n an Automotive Society." Proceedings National Conference on the Aging Driver, AMA, AAMVA (Morton Grove: Health and Safety Associates, 1974), p p .y i-8 4 . 93 Unpublished Reports, Materials and Interviews Hayes, Joseph. "Senior Citizen Aid Program." of State, 1973. (Mimeographed.) Hayes, Joseph A. 1978. Personal Interview. Lucia, John. Personal Interview. 1978. McDole, T. L. 1978. Telephone Interview. Lansing: Department Lansing, Michigan, January 20, Lansing, Michigan, January 20, Ann Arbor, Michigan, March 28, Michigan Secretary of State. "Analysis of Older Driver Answers on Renewal Test Questions." Lansing: Department of State, 1973. (Mimeographed.) Michigan Secretary of State. "Older Drivers' Renewal Results." Lansing: Department of State, 1978. (Mimeographed.) Nolan, Robert 0 ., et a l. "Senior Driver Project." East Lansing: Highway T ra ffic Safety Center, Michigan State University, 1975. (Mimeographed.) Plxley, Jean. 1978. Personal Interview. Lansing, Michigan, April 10, Scoring Office. "Item Analysis." East Lansing: University, 1977. (Mimeographed.) Michigan State APPENDICES APPENDIX A ITEM DIFFICULTY AND DISCRIMINATION 95 ITEM DIFFICULTY AND DISCRIMINATION Item Number Item D lff1cu ltyt Item D1scr1minations Item Number C-78 C-33 C-27 C-38 A-13 C-63 A-45 B -4 C -ll C-15 C-53 B-70 B-21 C-43 B-15 C-47 C-51 C-54 B-10 B-26 C-42 C-55 B-75 C-82 A-22 B—14 B-17 C-16 C-22 B-32 C-45 C-77 C- 9 B-12 A-39 A-50 C-44 90 87 83 81 77 77 73 67 6? 67 67 67 65 65 63 63 63 63 62 62 62 62 62 62 60 60 60 60 60 60 60 60 58 58 58 58 58 0* -29* 15 36 29 7 15 15 57 0* 43 43 22 21 -14* 50 36 57 - 7* 65 50 36 29 50 - 7* -21* 21 72 35 36 0* 21 21 0* 50 21 64 B-78 A-19 C-30 B-39 B-52 C-46 B-22 B-31 A-51 C-64 C- 6 A-47 C-62 A-73 A- 7 C-31 B-38 B-64 C-71 B-55 A-21 C-26 B-48 A-65 B-54 B-67 C-72 A- 5 B- 2 C- 8 C-19 A-34 B-33 B-61 C-80 A- 3 B-18 96 Item D1ff1cu ltyt 58 56 56 56 56 56 54 54 54 54 52 52 52 52 50 50 50 50 50 50 48 48 48 48 48 48 48 46 46 46 46 46 46 46 46 44 44 Item D1scr1m1 nations 72 0* 72 58 79 35 21 - 7* 21 65 57 28 14 7 58 50 50 58 43 7 329 36 21 50 35 50 43 35 14 64 35 57 36 14 57 72 14 97 Item D if f ic u lt y and Discrim ination (continued) Item Number B-23 C-18 C-20 C-21 B-42 B-45 B-79 C-70 C-79 B-20 B-30 C-39 A-44 B-43 B-51 C-76 A- 8 B- 5 C- 4 B-34 C-36 A-63 C-65 A-80 A-82 B- 8 A-18 B-24 C-23 C-34 C-40 8-71 B-80 B-82 B- 1 A-25 A-28 B-27 C-14 C-32 C-41 A-48 Item D1ff1cu ltyt 44 44 44 44 44 44 44 44 44 42 42 42 42 42 42 42 40 40 40 40 40 40 40 40 40 38 38 38 38 38 38 38 38 38 37 37 37 37 37 37 37 37 Item D1scr1m1nations 21 50 57 57 72 65 43 43 65 0* 14 36 50 50 50 64 50 -14* 22 57 57 14 72 72 7 50 50 7 57 36 22 36 64 14 -28* 71 50 35 50 28 22 50 Item Number . A-62 A-64 A-71 C-69 B- 6 C-10 C-12 C-17 B-41 C-35 B-47 C-48 C-60 B-68 B-81 C-73 C-37 A-49 A-52 B-60 A-70 A-74 B-66 A- 4 A-10 A -ll B- 9 C- 7 B-50 A-54 A-55 A-59 B-63 C-56 A-76 B-74 A- 1 A- 9 A-15 A-26 B-19 C-24 Item D iff1cu ltyt 37 37 37 37 35 35 35 35 35 35 35 35 35 35 35 35 33 33 33 33 33 33 33 31 31 31 31 31 31 31 31 31 31 31 31 31 29 29 29 29 29 29 Item Discr1m1nations 43 57 57 43 43 64 93 22 50 86 43 29 65 43 50 42 79 29 43 36 36 36 57 57 36 21 -14* 43 50 79 65 50 29 50 43 7 -22* 43 50 50 22 36 98 Item D if f ic u lt y and D iscrim ination (continued) Item Number Item D1ff1c u lty t A-40 A-46 B-46 C-49 B-59 B-62 B-72 B-73 A-20 A-30 B-13 B-44 A-56 C-66 C-67 A-37 B-35 C-57 A-79 B-77 C-74 A- 6 C- 1 C- 5 A-27 A-31 B-25 C-25 C-29 A-36 B-36 B-40 B-65 C-52 C-59 C-61 B-69 B- 7 A-23 B-16 C-28 29 29 29 29 29 29 29 29 27 27 27 27 27 27 27 25 25 25 25 25 25 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 21 21 21 21 Item D1scr1m1nations 57 57 22 8 50 36 22 43 50 50 8 28 50 64 50 29 29 72 64 22 50 64 14 43 36 22 22 43 50 57 64 43 29 36 50 57 29 36 22 0* 57 Item Number A-53 A-60 B-53 B-56 B-76 C-75 A-12 A-16 A-58 A-61 B-58 A-78 A-32 A-38 B-49 C-50 B-57 A-67 A-17 B -ll B-28 C-13 A-41 A-43 A-57 A-72 A- 2 A-24 B-29 A-75 C-81 C- 3 B-37 C-58 A-66 A-68 A-81 A-33 A-77 C-68 A-14 Item D1ff1cu ltyt 21 21 21 21 21 21 19 19 19 19 19 19 17 17 17 17 17 17 15 15 15 15 15 15 15 15 13 13 13 13 13 12 12 12 12 12 12 10 10 10 8 Item Dlscrlminations 57 50 57 57 15 50 71 43 50 29 50 57 43 43 14 50 0* 29 43 14 15 43 43 36 50 36 14 43 14 43 50 29 14 29 36 43 22 36 22 36 21 99 Item D if f ic u lt y and Discrim ination (continued) Item Number Item Discrimi­ nations Item D1ff1cul ty t A-29 A-42 C- 2 6 6 4 Key: 21 21 14 * A B C t - Item Number A-35 A-69 B- 3 Item D lf f lcultyt 4 4 2 Item D1sc1m1natlonS 14 14 7 A discrimination value of 0 or less Test Form A Test Form B Test Form C Item d iffic u lty —proportion(percentage) of subjects who missed the Item S - Item discrimination—how well an Item performed APPENDIX B SAMPLE DRIVER RECORD 100 SAMPLE DRIVER RECORD 04/10/78 9090909-0909090909 R-OPER 80 051805 12345 E. TURNER 012345 K0671 24-40 D-000-000-000-000 Doe, Jane LANSING 48900 33 CORRECTIVE LENS ADDRESS HISTORY 000000 LANSING MC SOS INQ #1234 K3224 110777 013073 IMPROPER LANE USE 101 F APPENDIX C LETTER TO MR. STEVENS 102 MICHIGAN STATK UNIVERSITY e a s t l a n s in g • M ic h ig a n i m i « C O N T IN U IN G E D U C A T IO N S E R V IC E • H IG H W A Y T R A F F IC S A F E T Y C E N T E R » K E L L O G G C E N T E R March 31, 1978 Mr. George Steven3 Driver and Vehicle Administrator Michigan Department of State Lansing, Michigan *1-8918 Dear Mr. Stevens * I am a doctoral student at the Highway Traffic Sefety Center of Michigan State University. I am Interested In completing a research project dealing with the general level of driving knowledge In motor vehicle operators age 6 5 and older In Ingham County, Michigan. A research project of this kind Is required for the degree Ph.D. In traffic safety. The proposed research Is to be conducted under the super­ vision and approval of the Highway Traffic Safety Center and Michigan State University. The project will be super­ vised by a four man committee consisting of 1 Dr. Robert E. Gustafson, Chairman, Dr. Norman T. Bell, Dr. Robert 0. Nolan and Dr. Donald L. Smith. The researcher will be Thomas Miller. The title of my proposed research will bei "Inventory of Critical Driver Knowledge for Motor Vehicle Operators Age 6 5 and Older In Ingham County, Michigan." This letter Is to request use of computer time to generate subjeots for this dootoral dissertation at Michigan State University. After consultation with Mr. John Luola It was determined that the following procedure would be the most cost effective method of obtaining subjeots for this research. Your approval is requested for the following 1 1. Random selection of two tapes of driver records. 2. From the two selected tapes print driver records for all drivers born in or before 1913 that now reside In Ingham County, Michigan. 3. Include In the driver records all accident histories for these subjeots. (This will be one of the study groups in the research design.) 4. Run the driver records on or before April 10, 1978. 103 Page Two Mr. George Stevens 5* Allow these Identified drivers to be used as the subjects for this proposed research project. The project will Involve the administration of a validated , standardized driver knowledge test to a group of randomly selected subjects from the above group. The experimental treatment will consist ofi An article In the State Journal and senior citizen newsletters ‘describing the proposed research! A letter addressed to the selected subjeots requesting their participation! A phone call requesting a time for their participation! A one hour testing time as agreed upon by the phone calli and a follow-up letter thanking them for their partici­ pation and advising them of the results of the experiment. It Is estimated that two tapes will be used and that between 700 and 800 driver records will be printed in this manner. All driver records will be kept confidential. All driver records will be returned to your department at the conclusion of this study* I will be glad, at your convenience, to discuss this proposed research with you. A copy of the results of this study will be sent to your office and made available to the people of Michigan. Again, the subjeots In this study will remain anonymous. Sincerely, y jr f j/ y o u ) yyiic&Aj Thomas L. Miller Dr. Robert E. Gustafson, Professor Committee Chairman Mr. Fred E. Vanosdall, Acting Director Highway Traffic Safety Center 104 APPENDIX D LETTER TO MS. OWEN AND NEWSPAPER ARTICLE 105 Aorll 21, 197° Marlon Owen Tri-County Office on Aging 505 V/, Allegan Lansing, Michigan 48933 D e a r Ms. Owent Here Is the notice for the Senior Forum of the State Journal. 24, 1979. I will begin the experiment on Monday April Please run this notice In the Senior Forum as soon as possible. V 0 T_I_ C 5 A driver knowledge research project is being conducted by Thomas Miller of Michigan State University. About 160 Ingham County senior drivers will be asked to give one hour of their time to fill out a driver knowledge Inventory. It Is expected this project will provide Information to help senior drivers maintain their driver license longer, have their Insurance premiums reduced and be safer drivers. It Is urged that you participate in this project when asked. The Information you provide can help to make Michigan a safer place for everyone to drive. Thank You, a yjf\0»jO 4 Thomas Miller 106 APPENDIX E SUBJECT CONTACT LETTER 107 My name is Thomas Miller, 1 am doing a graduate research project to obtain a Ph.D. in traffic safety at Michigan State University. This research project is important because it is expected to produce information that will help drivers age 65 and over. This project is considered valuable by the Michigan State University Highway Traffic Safety Center and Office of Lifelong Education Programs. The Michigan Secretary of State also supports this project. (See the enclosed letters.) The purpose of this project is to find out how much all Ingham County drivers age 65 and over know about driving. It is not possible for me to talk to all drivers age 65 and over in Ingham County. Therefore, you have been selected to be part of a sample needed to complete this project. I need one hour of your time to help answer a. driver knowledge inventory. This is not a driver license test. Sometime in the next week I will contact you by telephone to find out if you will agree to fill out the inventory. If you agree, a convenient time and place for you to help will also be arranged. There will be no cost to you for your participation in this project. Your name will not be recorded or used in any manner when the results of this project are reported. Your kind assistance in this project will be greatly appreciated. Thank you. Thomas Miller 108 APPENDIX F LETTER FROM DEAN HUNTER 109 MICHIGAN STATE UNIVERSITY LIFELONG EDUCATION PROGRAMS • OFFICE OF T H E DEAN EAST LANSING • MICHIGAN • 4M24 KELLOGG CENTER A p r il 15, 1978 Dear Ingham County R esid en t: T h is l e t t e r Is to In tro d u c e Thomas M i l t e r . He Is doing a g ra d u a te research p r o j e c t In t r a f f i c s a f e t y here a t Mlchtgan S t a t e U n iv e r s i t y . We fe e l t h is p r o j e c t w i l l make a v a lu a b le c o n t r ib u t io n to t r a f f i c s a f e t y in M ic h ig a n . You have been computer s e le c te d to re p re s e n t 150 Ingham County d r iv e r s In t h i s p r o j e c t . The o n ly th in g you w i l l be asked to do as a p a r t i c i p a n t o f t h i s p r o je c t Is t o f i l l ou t a one hour d r iv in g In v e n to ry . Your h e lp Is needed to make t h i s p r o je c t a success. And, your p a r t i c i p a t i o n In t h i s p r o j e c t w i l l b r in g you a t le a s t these two b e n e f it s : By com pletin g t h i s In v e n to ry you w i l l r e fr e s h your d r i v i n g knowledge f o r your n ext d r i v e r lic e n s e e x a m in a tio n ; and, th e knowledge gath e re d by t h i s In v e n to ry wt 11 make M ichigan a s a f e r p la c e f o r a l l o f us to d riv e . P lease h e lp us and the d r iv e r s o f M ichigan by ta k in g p a r t In t h i s p r o j e c t . S in c e r e ly Armand L. H unter Dean 110 APPENDIX G LETTER FROM MR. AUSTIN 111 M IC H IG A N DEPARTMENT OF STATE R IC H A R D H . A U S T IN L A N S I N G , M I C H I G A N 4BD18 f t t e f t n A R f O f ftTATC April 24, 1978 Dear Michigan Driver: I am concerned that sometimes not enough is being done to help senior drivers in Michigan. I feel that many times, in spite of our best intentions, we f a il to understand the special problems faced by drivers over 65. Therefore, I would lik e to ask you to help by p a rtic i­ pating in a study being conducted by Thomas M ille r, a graduate student a t Michigan State University. Mr. M ille r w ill contact you in the near future to schedule approximately one-hour of your time to f i l l out an Inventory of your knowledge concerning Michigan's tr a ff ic law and safe driving practices. Your p a rtic i­ pation 1n this study is important as 1t w ill help us understand better what special materials or special programs may be needed to help senior drivers operate a vehicle more safely. The study 1s in no way connected with your license renewal. I hope you w ill make time to participate. You have n\y thanks. Richard H. Austin Secretary of State 112 "Sctftiy B tllt and SUvrr Spttdt Sap* L in t" APPENDIX H DEMOGRAPHIC DATA SHEET 113 MICHIGAN STATE UNIVERSITY DEMOGRAPHIC DATA SHEET (Do NOT Write Your Name On This Sheet) Do you own a motor vehicle? ___________ How many miles do you drive in a year? ___________ How many years have you been driving a motor vehicle? Number of days that you drive each week? __________ What is your marital status? ___________ Have you ever attended a driver education or _______ driver refresher class? How many accidents have you been Involved In (as the driver) 1n the la s t two years? How many tr a ffic tickets (do not count parking tickets have you received 1n the la s t two years?___________________ ____ What 1s the highest grade level you attended In school?_______________________ How often, i f at a l l , do you use a seat belt when you drive a motor vehicle? How often, 1f at a l l , do you use a seat belt when you ride 1n a motor vehicle? Why did you participate 1n this study? Turn the page and f i l l 1n the knowledge Inventory....................... MF/YN/ABC 114 APPENDIX I FORM A, B AND C OF THE KNOWLEDGE INVENTORY 115 KNOWLEDGE INVENTORY Thank you for participating 1n this study. Your help 1n this project w ill provide Information that w ill be of benefit to a ll drivers age 65 and older. This 1s a research project designed to find out how much 1s known by a ll drivers age 65 and older 1n Ingham County, Michigan. You were selected 1n a random process and your answers represent those of 150 other drivers age 65 and older 1n this County. This 1s not a driver license test. Your name 1s not being collected with the“"fiiventory results and, therefore, can not~Ee reported to the Secretary of State's office. Please f i l l In the data sheet on page two. Then turn the page and begin answering the knowledge Inventory. Pick the best answer for each question and please answer a ll questions. There 1s no time lim it for taking this Inventory. You may take a coffee break at any time during the session. Please feel free to ask any ques­ tions while taking this Inventory. Please do not talk to anyone about the contents of this Inven­ tory u ntil you receive the study results by mall. They w ill be sent to you 1n September, 1978. Again, your name w ill be kept confidential and not shown to any o ffic ia l of the State. Please answer a ll questions by circlin g the le tte r of the best answer to each question as follows: * * * EXAMPLE QUESTION * * * D 88. You should drive: a) bj cj d) At the posted speed lim it, About 5 mph below the speed lim it, About 5 mph above the speed lim it, According to the road and weather conditions. Turn the page and f i l l 1n the data sheet..................... 116 117 A 13. I f you come to an Intersection that 1s hard to see around because of trees or buildings: a) b) c) d) A 14. I f an oncoming vehicle has started to turn le f t In front of you: a) b) cj d) A 15. Proceed as 1f there was a yield sign at the intersection. Stop near the center of the Intersection and then continue when i t 1s safe. Slow down and blow your horn to warn drivers who cannot see you. Stop at the Intersection and edge forward slowly. Speed up to get by him before he makes the turn. Slow down and allow him to turn 1n front of you. Steer to your right to get around him. Steer to your l e f t to get around him and allow him to turn. When turning l e f t at an intersection: a) b) c) d) You have the right-of-way over oncoming tr a ffic . You should blow your horn and proceed with caution. Check cross tr a ff ic from both directions. Pull halfway Into the intersection and edge Into cross tr a ffic . 118 B 41. Before leaving the road toavoid a head-on crash you should slow down by: a) b) c) d) B Pumping the brakes. Applying constant pressure on the brakes. Turning o ff the engine. Shifting Into neutral. 42. When approaching a tr a ffic accident or f ir e you should: a) b) c) d) B 43. I f you pass pedestrians near the road at night you schoul: a) b) c) d) B 44. Stop and o ffe r your help to the police. Turn on your emergency flashers before you drive by. Drive closer than usual to the vehicle 1n front of you. Slow down and watch fo r people near the scene. Turn o ff your headlights i f there are lights on the street. Use your high beam headlights i f there are no oncoming vehicles. Only use your parking lig h ts. Keep your headlights on low beam. When driving at dusk or dawn on a dark day: a) b) c) d) Turn on your parking lig h ts. Keep your sunglasses on to cut down headlight glare. Turn on your lights on high beam. Turn on your lights on low beam. 119 C 77. This sign means: a) b) c) d) C 78. ✓ 'T H * U H IG H W A Y F lH E flD This t r a f f ic signal means: a) b) c) d) C 79. Watch fo r cross t r a f f ic ahead. Stop sign or signal ahead. No through t r a f f ic ; prepare to turn. Prepare to change routes. Slow down and continue with caution through the Intersection. Speed up and continue through the In te r­ section before the lig h t changes to red. Stop before entering the Intersection 1f you can safely do so. Stop Immediately; do not continue through the Intersection. These lane lines mean: a) b) c) d) Lane changing permitted fo r a ll vehicles. Trucks may not change lanes; other vehicles are permitted to do so with care. Changing lanes 1s not allowed. Changing lanes 1s permitted 1f done with care. YELLOW (STEADY)