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thesis entitled

THE EFFECTS OF TIME COMPRESSED
VIDEOTAPE PRESENTATIONS ON
COMPREHENSION OF
ELEMENTARY PUPILS

presented by

James Earl Sanders

has been accepted towards fulfillment
of the requirements for

ph D ' degree in Education

“”7; MM X/é’g
/ Major professor /

   

Date 5/2/75 ’

0-7639

 

 

 

ABSTRACT

THE EFFECTS OF TIME COMPRESSED VIDEOTAPE PRESENTATIONS

ON COMPREHENSION OF ELEMENTARY PUPILS ‘
by

James E. Sanders

The purpose of this study was to investigate the effects
of time compression of a videotape presentation on the
comprehension of subject matter by fourth-grade elementary
school pupils. The major concernin the study was to deter-
mine if the comprehension of pupils receiving compressed

videotape information differs significantly compared to
. pupils receiving the same information by videotape at the
normal speaking rate. Another concern was to analyze the
post-test scores of pupils taking a pre-test and those not
taking a pre-test to determine if there was a significant
difference.

A sample population of eighty randomly selected subjects
was randomly assigned to eight treatment groups. The treat-
ment groups were classified by compression levels of O, 20,
40 and 60 per cent and pre-test or no pre-test. All groups
received the same content message at different rates of
compression.

I The videotape, "The Inclined Plane: A Simple Machine,"

served as the stimulus material for the study. The original

James E. Sanders

narration was recorded at 127 words per minute and was com-
pressed to 154, 206 and 309 words per minute using the
sampling method at the Perceptual Alternatives Laboratory, ‘
University of Louisville, Louisville, Kentucky. After viewe
ing the videotape, the subjects were given a comprehension
test. The tests were scored and the scores were then com-
piled for analysis.

The analysis of variance was used to determine if there
was a significant difference in the comprehension scores of
pupils viewing a videotaped program at the normal oral
speaking rate and the comprehension scores of pupils view-
ing 20, 40 and 60 per cent time-compressed versions. The
Duncan's Multiple-Range Test was used to determine between
which compression rates there was a significant difference
in comprehension scores of subjects. The analysis of
variance was also used to determine if there was a signif-
icant difference in the comprehension scores of pupils
taking a pre-test and those not taking the pre-test. The
.05 level of confidence was used to test the two hypotheses
and the Duncan's test for significance.

The analysis of the data concerning the comprehension
scores of pupils viewing a videotaped program supported the
following conclusions:

1. The information processing system was a single-
channel system and was selective at any given time among the
different cues. The significant decrease in comprehension

scores was above the 275 words per minute level. The results

James E. Sanders

of audiovisual compression was similar to audio only
compression.
2. The administering of a pre-test to fourth-grade
pupils did not sensitize pupils to subject matter of a com-
pressed videotape presentation and did not invalidate or

significantly affect the post-test scores.

THE EFFECTS OF TIME COMPRESSED VIDEOTAPE PRESENTATIONS
ON COMPREHENSION OF ELEMENTARY PUPILS

By

.\
James E? Sanders

A DISSERTATION
Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of
DOCTOR OF PHILOSOPHY

College of Education

1975

ACKNOWLEDGMENTS

This study would have been impossible without the contin-
uous help, encouragement and support of many people, and the
author would like to express his appreciation to all of them.

First, thanks go to Dr. James L. Page, Chairman of the
Guidance Committee. He has provided a great deal of guidance
and encouragement throughout the doctoral program. The
remainder of the committee; Dr. Paul W. F. Witt, Dr. Norman
T. Bell and Dr. Dale Alam have also been very helpful and
cooperative.

Thanks go, too, to Dr. Elwood E. Miller, former professor
at Michigan State University, and to Dr. Charles Anderson,
Dr. Ronald Adams, Mr. F. S. Faries and Mr. Thomas Foster,
faculty members at western Kentucky University, and Mrs.
Connie Foster for their continued assistance and encouragement.

Appreciation is also expressed to all those pupils,
teachers and administrators of the Bowling Green City School
System and the Jones-Jaggers Laboratory School who were so
very cooperative with the author in the collection of the
data.

Finally, immeasurable appreciation is extended to my
wife Anita and my sons Barry and Steven for their assistance

and encouragement throughout the doctoral program.

ii

TABLE OF CONTENTS

CHAPTER
LIST OF TABLES . . . . . .
LIST OF FIGURES. . . . .

 

I. TI‘IE PROBLEM. o o o o o o a

Purpose of the Study. .
Need for the Study. .

Theory Underlying the Study

Hypotheses. . . . . . .
Definitions . . . . . .

0

Organization and Overview

II. REVIEW OF RELATED LITERATURE

III. DESIGN OF THE STUDY. . . .

Introduction. . . .
Population. . . .
Design and Analysis
Stimulus Material .
Audio Development .
Visual Development.
Instrumentation . .
Procedures. . .
Statistical Hypotheses
Summary . . . . . . .

IV. ANALYSIS OF RESULTS. . . .
Introduction. . . . . .

Analysis of Data. . . .
smary O O O O O O O 0

iii

0

O O O O O O O O O O O

Page

vi

\OOCLOQWl—‘l-J l—’

10

TABLE OF CONTENTS--Continued

CHAPTER
V. SUMMARY AND CONCLUSIONS . . . . . .
Findings and Conclusions . . . .
Discussion of Results. . . . . .
Implications for Education .
Suggestions for Further Research
BI BLIOGRAPI-IY O O O O O O O O O O O O O O

APPENDICES

A. STIMULUS MATERIAL SCRIPT. . . . . .

. PILOT STUDY COMPREHENSION TEST. . .

. ITEM DIFFICULTY AND DISCRIMINATION INDEX.

B
C
D. PRE-TEST AND INSTRUCTIONS . . . . .
E. COMPREHENSION TEST AND INSTRUCTIONS

iv

0

1+7
50
5h
55
59

LIST OF TABLES

TABLE Page

1 Reliability Analysis of the Comprehension
T831: 0 0 O O O O O O O O O O O O O O O O O O 27

2 Analysis of Variance for Comprehension
scoreSo O O O O O O O O O O O O O O O O O O 33

3 Mean Comprehension Scores for Each Word
Rate 0 O O O O O O O O O O O O O O O O O O O 3 h

A Comparison of Comprehension by Treatment
through the Duncan's Multiple-Range Test. . 3h

5 Mean Comprehension Scores for Pre-Test/
No Pre-Test Groups. . . . . . . . . . . . . 36

LIST OF FIGURES

FIGURE Page
1 DeSign Of the Study. 0 O O O O O O O O O O 20

vi

CHAPTER I

THE PROBLEM

Purpose of the Study

The purpose of this study was to investigate the effects
of time compression of a videotape presentation on the com-
prehension of science subject matter by fourth-grade elemen-
tary school pupils. The major concern in the study was to
determine if the comprehension of pupils receiving compressed
'videotape information differed significantly compared to
pupils receiving the same information by videotape at the
normal speaking rate. Another concern was to analyze the
'post-test scores of pupils taking a pre-test and-those not
taking the pre-test to determine if there was a significant

difference.

Ngegffor the Study

How can information best be transmitted with speed and
reliability? This problem of efficiency in learning has
been of considerable interest in the United States. Yet
the knowledge explosion unparalled in the history of human
existence has hindered attempts at efficiency. During the
past twenty years, however, since Fairbanks and Associates
announced the successful development of the speech compressor,
time-compressed speech has proved to be an efficient and

l

2
rapid means of audio transmission.1 In addition, a study
by Woodcock and Clark has also provided evidence that high-
speed listening can be an efficient means of learning for
elementary school pupils.2

The large volume of information that must be transmitted
daily, the increased cost of communicating such information,
the lack of time available to acquire such information, and
,staying abreast of essential findings have constituted a
seemingly insolvable problem for classroom teachers.

Until now almost every approach to solving this prob-
lem has relied primarily upon the conventional communication
technology and techniques. Very few, if any, really revolu-
tionary means for handling information and time barriers
have been developed. The increased availability of port-
able videotape units for small group and individual use in
schools has accelerated the demand for videotapes for teach-
ing and learning. Consequently, an efficient method of pre-
senting audiovisual material is desirable. Perhaps, then,
time compression of information presented by means of
television is the solution for efficient and effective learn-

ing without significant loss of comprehension.

 

lC. Fairbanks, w. L. Everitt and R. P. Jaeger, "Method
for Time or Frequency Compression--Expression of Speech."
Transactions of the Institute of Radio Engineers Professional
Group on Audio, 1954, AU 2, pp. 7-12.

2Richard W. Woodcock and Charlotte R. Clark, "Compre-
hension of a Narrative Passage by Elementary School Children
as a Function of Listening Rate, Retention Period, and I. Q."
The Journal of Communications, XVIII(September, 1968),

p. 259.

3
Theory Underlying the Study

In the review of related research concerning audio and
audiovisual compression, many of the studies have been re-
ported withOut any predictions based on theory. Nearly all
of these have simply reported the results of experiments
which lack hypotheses derived from theory.

The theoretical orientation of this study lay within
the general framework of the cue summation principle of
learning theory as interpreted by Severin. Specifically,
Severin says this principle of learning theory predicts that
learning is increased as the number of available cues or
stimuli is increased.3 Hoban and VanOrmer cited studies
indicating that pictures added to auditory material were more
effective than auditory material alone.h Severin, in a sum-
mary of research by Wesley and Barrow, reported that tele-
vision versions produced greater learning than radio versions
of an information program and that concepts presented in both
audio and video were more salient than concepts presented by
audio only.5

Miller also suggested the possibility of applying the
cue summation principle to multiple-channel communication,

since related cues in two channels should summate and result

 

3Werner Severin, "Another Look at Cue Summation."
AV Communication Review, XV(Fall, 1967), p. 237.

#C. F. Hoban and E. B. VanOrmer, "Instructional Film
Research." (University Park: Pennsylvania State University)
SDC 269-7-19, 1950, p. 143.

A
in a gain while unrelated cues should cause interference
and a loss.6 Cue summation, however, predicted that learn-
ing was enhanced by a multi-modality communication with
additional relevant cues.

In yet another study, Broadbent has proposed that a
nervous system acts as a single channel with a limited
capacity.7 ‘In other words, information from only one source
igains access to the nervous system at any given time. The
model applies only when the information handling capacity of
the system is near to being fully utilized. Broadbent goes
on to predict that the system may jam if two or more messages
with high information content are received through two dif-
ferent internal channels at the same time. According to
Travers, the single-channel communication theory is in accord
with theoretical models developed by psychologists inter-
ested in perception and information transmission and with
emerging theoretical conceptions in physiology.8

Cherry, a communications engineer, has also concluded
that the utilization of information by humans can be repre-

sented by a single-channel system.9

 

6Neal E. Miller, "Graphic Communication and the Crisis
in Education." AV Communication Review, V(December, 1957),

Po7o’
7D. E. Broadbent, Perce tion and Communication.
(New York: Pergamon Press, 1953). P. 297.

8Robert M. Travers, "The Transmission of Information
to Human Receivers." AV Communication Review, XII(Winter,

1964). p. 374.

9E. C. Cherry, "Some Experiments on the Recognition
of Speech with One and Two Ears." Journal of the Acoustical

Societ of America, XXV(l953), p. 975.

5

All of these models of a single channel through which
all modalities enter the central nervous system contained
a "filter" of one type or another to exclude stimuli.

Van Mondfrans and Travers concluded that "the use of
two sensory modalities has no advantage over one in the
learning of material which is redundant across modalities."lo
Their work did not deal with material presented through two
channels which are non-redundant; instead, they concentrated
on verbal material in both channels and avoided the use of
pictorial material.

In addition to the previous researchers, Jester and
Travers found the audiovisual combination to be superior to
a single channel on a reading test only with speeds in excess
of 200 words per minute.11 Travers concluded that there was
no advantage from redundant material in two channels unless
unusually high speeds were used. The present study was
designed in accordance with Travers in that there was complete
between-channel redundancy only when spoken and printed words
were presented simultaneously.

In reviewing the cue summation theory of learning and
related research three possible theoretical positions emerged

for what would happen when compressing audio plus video infor-

mation. These theories are as follows:

 

loAdrian Van Mondfrans and Robert M. W. Travers,
"Learning of Redundant Materials Presented Through Two Senso-
ry Modalities." Perceptual and Motor Skills, XIX(l96L),

P. 744.

lTravers, "The Transmission of Information," p. 375.

6

(l) A summation of relevant cues from audio and video
channels will allow a greater rate of compression without a
decrease in comprehension because cue summation predicted
that learning increased by a summation of relevant cues
from both channels. .

(2) The result of compression of audio and video infor-
mation is very similar to that of audio compression only
since the information processing system is a single-channel
and at any given time is selective among the different cues.
Therefore, if the cues in all channels are related, the re-
ceiver is selective as to the cue he attends to in terms of
learning the perceived task. 7

(3) Also, the summation of cues from the audio and
video channels, if they are related, causes the threshold at
which the comprehension of compressed audiovisual materials
to be at a compression rate lower than for audio compressed
materials only because the total number of cues available is
greater than channel capacity.

The position taken in this study is that the results of
audio and video compression of information is Very similar
to that of audio only compression, since, according to

Broadbent12

and Cherry,13 the information processing system
is a single-channel system and is selective at any given

time among the different cues.

 

12Broadbent, Perception and Communication, p. 297.

l3Cherry, "Experiments on Recognition of Speech,"
P- 9750

7
A study by Foulke, Amster, Nolan and Bixler in which
both technical and literary listening selections.were used
found c0mprehension to be only slightly affected by using
word rates up to 275 words per minute. However, in the
range extending from 275 to 375 words per minute, they found
an accelerated decrease in comprehension as the word rate in-
creased.lh In another article Foulke reported that losses
in listening comprehension did not reach statistical signif-
icance until a word rate of 300 words per minute was passed.
Similar findings were reported by Fairbanks, Guttman and
Miron16 in their study of the effects of time compression
upon comprehension and also by Foulke and Sticht.l7 Both
of the articles revealed that the comprehension of com-
pressed speech is acceptable up to around 250-275 words per
minute. Thereafter, there is a rapid decline in comprehen-
sibility.
With the assumption of a single-channel system for
compressing information, the prediction here was that the

_._

1"Emerson Foulke and others, "The Comprehension of
.Rapid Speech by the Blind." Exceptional Children, XXIX
(1962), p. 134. - 1‘

15Emerson Foulke, "Listening Comprehension as a Func-
‘tion of Word Rate." The Journal of Communication, XVIII

(1968), p. 203.

, l6Grant Fairbanks, Newman Guttman, and Murray S. Miron,
Tflffects of Time Compression upon the Comprehension of Con-
nfiacted Speech." Journal of Speech and Hearin Disorders,

X3CII(March, 1957), p. IO.

l7Emerson Foulke and Thomas G. Sticht, "Listening Rate
Plreferences of College Students for Literary Material of
Moderate Difficulty," Journal of Auditory Research, VI

(1966). p. 397.

8
audio plus video information such as videotapes resulted
in a significant decrease in comprehension at a similar
word per minute rate of presentation as that for audio only
compression. Therefore, the following hypotheses were

formulated.

Hypotheses
In addition to finding out channel capacity of time
compressed videotaped presentations this study was designed
to determine if there was a significant difference in post-
test scores of subjects taking a pre-test and those not
taking a pre-test. The hypotheses considered in this study
were as follows:

Hypothesis I---There will be a significant difference in ,
the comprehension scores for pupils viewing
a videotaped program at the normal oral
reading rate compared to comprehension

, scores of pupils viewing 20, AC and 60

per cent time-compressed versions. ‘The'
major difference will occur at the 60
per cent level.

Hypothesis) II--There will be no significant difference in
post-test scores of subjects taking a
pre-test and those not taking the pre-test.

Definitions
Specific terms used in this study are defined as

follows:

(1) Comprehension score was the score obtained on the
comprehension test.

(2) Compressed speech was tape recorded speech which
had undergone an increase in the rate of presentation by
deleting small portions of the signal and by connecting the
remaining sound elements to provide an uninterrupted message
without change in pitch.

9

(3) Normal oral reading rate was an oral word rate of
approximately 150 to 175 words per minute as read by a pro-
fessional reader. '

Organization and Overview

In Chapter I the general frame of reference for the
study is given, including the purposes of the study, need
for the study, theory, hypotheses, and definitions related
to the study. The literature related to the study is re-
viewed in Chapter II and involves the age level of the pupils,
listening comprehension and the various word rates in re-
lation to visual stimuli employed in previous studies. The
design of the study, reported in Chapter III, includes pop-
ulation used, design, analysis and stimulus development.
In Chapter IV the analysis of the data is the focus, and

Chapter V includes the summary and conclusion.

CHAPTER II

REVIEW OF RELATED LITERATURE

Until now, few studies have been conducted using com-
preSsed speech with accompanying time compressed visuals.
Furthermore, almost all of these studies have involved col-
lege level students or adults. In this review of literature,
research related to audio-only compression has not been re-
ported nor has the general development of the speech com-
pression process been included.

In 1949, Vincent, Ash and Greenhill reported the results
of their research which attempted.to determine the effects
on learning by increasing the concentration of facts in films.1
Four films on the subject of weather were prepared as follows:
a "long-heavy" version of 29 minutes which contained 22h
facts, a "long-light" version the same length but with 112
facts, a "short-heavy" version of 14 minutes with 112 facts,
and a "short-light" version with 56 facts in 1h minutes.

Conclusions based on the data were that packing more
information into a film yields only a slight increase in to-

tal measured learning. The "heavy-long" version, for instance,

 

1W. S. Vincent, P. Ash, and L. P. Greenhill, Relation-

ship of Length and Fact Frequency to Effectiveness of Instruc-
tional otion ictures, Special Devices Center, TechnicaI
Report SDC 269-7-19 (Port Washington, N. Y.: Special Devices
Center, 1950), p. 1A0.

 

lO

11
did not result in twice as much learning as the "short-heavy"

or the "long-light" versions, nor was there twice as much
learning as with the "short-light" film.

Nelson, Moll and Jaspen reported two experiments in
which the effectiveness of the aural and visual elements in
instructional films was compared to determine their relative
contributions to learning.2 Eight test groups were used
with various combinations of aural and visual stimuli.

These experiments showed that groups which both saw and
heard a film learned more than groups which only saw or heard_
the film.

The specific conclusions based on the data were that:

(1) significant learning accrued from the film as a whole

or from either the video or audio alone; (2) neither Channel
was consistently better than the other, although both chan-
nels together were consistently better than either one alone;
and, (3) more learning accrued when the two channels were

in harmony.

Research on the transmission of information conducted
at the University of Utah,3 was summarized in an article by
Travers. Although general in nature, the work contained spe-
cific references to compressed presentations involving read-

ing test passages displayed through hearing alone, through

 

2H. E. Nelson, R. M011, and N. Jaspen, Comparison of
the Audio and Video Elements of Instructiona i s, pecial
Devices Center, Technical Report 269-7-1B (Port Washington,
N. Y.: Special Devices Center, 1950).

3Travers, "Transmission of Information," p. 373-385.

12

vision alone, and through both hearing and vision. Travers
reported that:

At the slower speeds of 200 words per minute

or less no advantage was achieved through the audio-
visual presentation, but at higher speeds two things
began to happen. First, many subjects took obvious
steps to block one channel by closing the eyes or
covering the ears, and second, despite this block-
ing of one channel, the audiovisual transmission of
information turned out to be superior to the single
channel. Presumably, subjects tended to block the
information channel which was of least value to them.

Two sources of information coming through the
same sense modality or through different modalities
can be utilized simultaneously if the rate of trans-
mission of information is very low. At higher
speeds, where the information from a single source
is more than the processing system can handle,
switching from source to source may occupy a part
of the time available for taking in information. 4
This switching appears to be time out for learning.

In discussing time compression, Travers noted that com-
pression of information by the nervous system involved dis-
carding of less important information and retaining the more
important. He further observed that in the experiments re-
ported above, the comprehension of auditory presentation fell
off more rapidly than the comprehension of the visual presen-
tation and that the audiovisual presentation began to show
an increasing advantage over either of the single channel
presentations. Travers further commented that:

There are several factors involved here.

The first factor is undoubtedly the fact that the

speeding up of auditory material by time compres-

sion results in a loss of intelligibility, but

there is no corresponding loss through speeding
the presentation of visual material. The second

 

41bid., p. 373.

13

is that the eye can scan reading material in such
a way that the words or groups of words transmit-

ting the most useful information are more readily

received...A third factor is that most people have

had some experience in receiving information at

high speeds through the visual sense but few have

had comparable experience with high speed audio

transmission. A fourth factor is that the infor-

mation needed to identify a word transmitted

aurally takes an appreciable time to transmit,

but when the same word is transmitted visually the

entire information needed to interpret the word 5

arrives at the receptor level at the same instant.

This study described by Travers, however, involved
visual augmentation consisting of verbal material and not
pictorial information.

In another study, LOper sought to determine the possi-
bility of decreasing the amount of time required to present
factual material over a television system while holding the
comprehension at acceptable levels.6 Loper found that when
presentation rates of zero, one-third, and one-half were
used for a message presented either in an aural or a visual-
ly augmented aural form, the only difference between presen-
tation rates was in favor of the visually augmented aural
presentation at one-half compression. Furthermore, this
difference did not show up on the retention test immediately
following the presentation, but on a retention test admin-
istered two weeks after the original test. He concluded,

therefore, that visual augmentation did not aid comprehension

 

51bid., pp. 382-383.

6James L. Loper, "An Experimental Study of Some Effects
of Time Compression upon the Comprehension and Retention of
a Visually Augmented Televised Speech." Dissertation Ab-
stracts, XXVII(June, 1967), P. 4370-A.

1A
of compressed messages and aided retention of information
only at high rates of compression.

The research by Boyle was designed to investigate the
effects of variations in visual Stimulation on the listening
comprehension of compressed speech in fifth-grade pupils.
Three variations in visual stimulation were presented to
three groups of subjects, each group receiving a different
type. The visual treatments were: no visual stimulation,
irrelevant and unstructured visual stimulation, and relevant
pictorial visual stimulation. The four word rates were 178,
228, 278 and 328 words per minute. Each subgroup received
one of the four word rates. Boyle found that the decline in
comprehension was due to the increasing word rate only and
that there were no differences in groups receiving the same
word rate but different visual presentations.7

Watts found that the addition of slides to a previously
prepared lecture did not augment achievement of college-
educated Air Force officers.8 Watts pointed out that he know
beforehand that the slides did not carry any specific content
to strengthen the original stimulus. For this reason, the ‘
conclusion that slides themselves do not add to a compressed

speech presentation.would be incorrect. One important

 

7Virginia A. Boyle, "Effects of Variations in Visual
Stimulation on Listening Comprehension," CRCR Newsletter,
III(December, 1969), p. l.

8M.‘W. Watts, Jr., "Using Compressed Speech to Teach
Instructional Techniques to Air Force Officers." Presented
to the Second Louisville Conference on Rate and/or Frequency
Controlled Speech, (October, 1969).

15

sidelight of the research was the informal notation that

many of his subjects felt more "comfortable" when visuals

were added.9
In his investigation of slide-audio tape presentation

experienced in learning carrels and presented at compressed

(250 words per minute) and normal (150 words per minute)

rates of speech, Perry reported that:

At the .05 level it could not be demonstrated
that subjects experiencing a compressed speech slide-
audio tape presentation achieved higher mean scores
on recall or application tests than subjects ex-
periencing a normal speech slide-audio tape presen-

It was found significant at the .05 level that
subjects experiencing a slide-audio tape presentation
whether with normal or compressed speech achieved
higher mean scores on recall and applicatioE tests
than subjects who received no presentation. 0
Anderton sought to determine if a tape-slide instruc-

tional program designed to teach recognition of behavioral
objectives would be as effective when presented at higher
rates of speed. Secondary considerations of the study were

to determine if the use of pictorial embellishments (cartoons)
contributed to learning, if students learned more when infor-
mation was presented twice at high speeds, if faster rates

of presentation withoug pictorial embellishments were more

effective than the original program.

 

9Ibid.

 

10Thomas K. Perry, "The Effects upon the Learner of a
Compressed Slide-Audio Tape Presentation Experienced in a
Learning Carrel as Measured by Recall and Application Tests,"
Unpublished Dissertation, 1970, pp. 65-66.

16

,The results showed that there was no significant dif-
ference in learning from a tape-slide instructional program

at different rates or from presenting materials twice at
high speeds rather than once at the original speed of the
recording. Regarding pictorial embellishments, there was no
significant difference in learning from a presentation at
faster rates, without pictorial embellishments, and the
learning resulting from presentation of the original program
at the normal rate.11
The principal problem in the study by Parker was to as-
certain the degree to which college students could recall
information presented in an uncompressed version and three
differently compressed versions of a 16mm film. Both the
audio and visual cues were compressed in varying degrees in
the experimental version. In this study the compression was
accomplished by eliminating every sixth, eighth and tenth
frame of the film. To the extent of his experiment, the
audio and video compression appeared to have little or no
effect upon information recall of college students partic-
ipating in the study. Parker further suggested that addi-
tional research was needed to determine the effects on

learning of compression in various types of media.12

 

11Ray L. Anderton, "The Effect of a Time-Compressed
Tape-Slide Instructional Program upon the Learner," Center
for Rate Controlled Recordings Newsletter, III(December,

9 pp. 2‘ 0

12John P. Parker, "The Effect of Varying Degrees of
Compression in a 16mm Sound Motion Picture upon Information
Recallé" Dissertation Abstracts, XXXII(December, 1971),
p. 291 ‘A0

l7

Benz designed a study to test the effect of transmitting
compressed speech along with a viSual complement on the com- .
prehension of factual material. In his research involving
a college level television lecture concerning maps at normal
rate and at one-third and one-half aural compression, Benz
reported significance was found between the aural-only and
aural-visual modes. He also observed that the one-third
Compressed aural-visual presentation was as effective as the
normal rate aural-visual presentation, while the aural-only
normal rate was significantly better than the aural-only one-
third compressed rate. The visual elements were an aid to
,learning in this instance. 9

Benz concluded that the television lecture presentation,
which required a visual complement, could be increased.in
word rate with a reduction in presentation time by one-third,
without significant loss in comprehension.13 A

In the review of related literature the studies were
primarily interested in determining if the addition of visual
stimuli increased the comprehension of compressed auditory
information. The majority of the studies did indicate that
there was at least some increase in learning by the addition
of the visuals, but in the light of the major concern of this
study, some disagreement might arise. In the studies re-

viewed in the literature, however, the intention was not to

 

13Carlton R. Benz, "Effects of Time-Compressed Speech
upon the Comprehension of a Visually Oriented Television
Lecgure." Dissertation Abstracts, XXXII(May, 1972),
p0 579‘Ao

l8

compare the comprehension scores of subjects receiving an
audiovisual presentation at the normal rate with subjects
receiving time compressed versions to establish a threshold
at which there is a significant difference in the scores.
In two of the experiments, however, there was no increase
in the learning that could be attributed to the addition of
the visuals to the compressed audio information. These.
findings tended to support the theoretical position of this
study that the results of audio and video compression of
information are very similar to that of audio-only com-
pression, since the information processing system functions
as a single-channel system and was selective at any given
time among the different cues.

In two other studies there was no significant difference
in the post-test scores when a slide-tape program was com-
pressed to 250 words per minute-and when a 16mm film was
compressed by the elimination of every sixth, eighth and tenth
frame. The word per minute rate in these last studies fell
below the generally accepted point of 275-375 words per min-
ute at which comprehension of compressed speech began to
show a significant decrease. Since the theoretical position
taken in this study is that the results of audio and video
.compression of information were very similar to that of
audio only compression, the 60 per cent compression rate
(309 words per minute) was chosen as an upper limit since
it did fall within the range at which one expects the compre-

hension of audio-only materials to decrease significantly.

CHAPTER III

DESIGN OF THE STUD

Introduction
The description of the population, the nature of the
stimulus material and the data collection instruments are
described in this chapter. Also the specific procedure,
experimental design and method of statistical analysis are

presented.

Population

The subjects for this study were selected from a popu-
lation comprised of fourth-grade pupils attending two
elementary schools in the Bowling Green City School System,
a south central Kentucky city of 40,000. Both male and
female pupils were involved. The two elementary schools
used in the study were randomly selected from six.

The total population of fourth-grade pupils in the two
schools was 132. Eighty pupils, randomly selected from the
population, were then randomly assigned to one of eight
treatment groups. Eight additional pupils were selected by
the same sampling procedures to serve as replacements; how-
ever, none of these pupils was needed when the data were

gathered.

20

One criterion in the selection of subjects was the
existence of an I. Q. score. Additional criteria used in
sample selection were the subjects' hearing and seeing abil-
ities. Health records revealed that the subjects selected
passed the tests for normal hearing and vision. Some, how-
ever, had normal vision only through the use of corrective
lenses. Other considerations were the subjects' previous
experience with compressed speech and prior knowledge of the
subject matter used in the stimulus material. During the
meeting with the teachers of the pupils used in the study
it was determined that none had to be eliminated as subjects
in the study because of prior experience with compressed
speech or prior knowledge of the subject matter used in the

stimulus material.

Design and Analysis
The design of the study and treatments are shown in‘
Figure 1. The eighty subjects were assigned to four compres-
sion groups and each group was then randomly divided into
two sub-groups. One sub-group took the pre-test and the
other group did not. For this study the zero compression

group was used as the control group.

 

 

Per Cent of Time Compression

 

 

0 2O 40 6O
Pre-test 10 10 10 10
No Pre-test 10 10 10 10

 

Figure 1. Design of the Studyo

21

The analysis of variance was used in order to investigate
the effects of time compression of a visual and aural presen-
tation on comprehension of subject matter by elementary
school pupils. This analysis was also used to determine if
a significant difference existed between the mean compre-
hension scores of subjects receiving a pre-test and those
not receiving the pre-test. In this study each cell con-
tained ten subjects. This design corresponds to Ferguson's
design for one-way analysis of variance.

'The level of significance test for each of the null
hypotheses for the main effects of Factor A, compression
rate, and Factor B, taking of a pre—test, was .05. Because
Of the relatively small sample size of each cell and the
brevity of the treatment, the .05 level for rejecting the
null hypothesis was chosen.

The data gathered in the study were transferred to com-
jputer punch cards and analyzed at Western Kentucky Univer-

sity‘s Center for Academic Computing through the IBM 371-65

computer system.

Stimulgs Material
Selection of the stimulus material was based on the
lfollowing criteria. First, the subject matter should be
Eappropriate for pupils of the fourth grade, and secondly, it

¢3hould not have been taught prior to the use of the stimulus

Imaterial.

1George A. Ferguson, StatiStics Anal sis in Ps cholo
iind.Education. (New York: McGraw-Hill Book Co., 1971),
0 200

22

The material was appropriate for fourth-grade pupils
because the subject of simple machines was taught in this
school system at the fifth grade level. An instructional
16mm film served as the model for the preparation of the
stimulus material in this study. The film, entitled Simple
Egghines: Inclined Planes, was produced by Coronet Films,
Inc.2 It was intended for use in science in grades three
through seven and contained more illustrations appropriate
to pupils of this age than did any other film on the subject
that was reviewed. The original version of the film was
black and white and contained many outdated pictures. The

content, however, remained appropriate and useful.

Audio Development
The person selected to read the script for the audio

portion of the stimulus material was given the script one

. week before the time of the recording session and was asked

to become familiar with it. The reader was instructed by

the developer to read the script in as normal a manner as
possible. The recording was under the supervision of an audio
technician to insure the best quality recording possible.

The original tape was recorded at fifteen inches per
Second. It was sent to the Center for Rate Controlled
Eipeech at the University of Louisville, Louisville, Kentucky,
where it was electro-mechanically compressed by 20, A0 and 60

F

2Coronet Films, Inc. Simple Machines: Inclined Planes.
(Cilicago: Coronet Films, Inc., 195C), é reel.

23
per cent of its normal playing time. These four tapes served
as the audio portion of the videotapes that were produced for

the stimulus material.

Visual Develppment

After the audio portion was developed, four visual seg—
ments were then produced to correspond to the original audio
and the three compressed audio tapes. In thevisual devel-
opment one major factor was the necessity of keeping all vis-
uals relative to the audio portion of the tape.

A graphic artist assisted in the preparation of the vis-
uals that explained the principles, concepts and descriptive
material within the videotape.

The master image recording at 0 per cent compression
was recorded on an Ampex Model VR-1200B quadraplex videotape
recorder. The compressed audio was pre-recorded on the video-
tapes from the compressed audiotapes before video compression
was started. The compression of the visual segments corre-
sponding in length to the time compressed audio was accom-
plished by using two Ampex VR-1200B quadraplex videotape
machines with electronic editing. The video editing was
scene by scene assemble editing from the original master
quadraplex tape to match the length of each individual audio
segment. No visual segment was totally deleted in the
compression process. The editing was the subjective judge-
ment of the author and the scenes selected best depicted the

video appropriate for the audio.

2A

The quadraplex tapes were duplicated to the Sony three-
fourths inch U-matic videotape format since this machine was
to be the means for delivery of the stimulus material to the
subjects. The three-fourths inch cassette format was chosen
because of its portability and reliability in image repro-
duction and the good quality of color reproduction.

I "The original videotape and the three compressed tapes
were recorded and edited in the Western Kentucky University

ITelevision Center.

Ipstrumentation

Two instruments were employed to collect the data need-
ed in this study. These instruments were the comprehension
post-test and the pre-test.
Comprehension Post-Test

A pilot study was conducted prior to the experiment in
order to construct the Experimental Comprehension Test.
Since there was no commercially available test of the material
presented by the stimulus videotape, a test was developed
to determine the pupils' comprehension of the subject matter.

Prior to the test construction a meeting with teachers
who taught fourth-grade science in the Bowling Green City
School System was held to assess the knowledge of fourth-
grade pupils on the subject of the simple machines. From
this information the original twenty item multiple-choice
test (see Appendix B) was constructed.

According to Chase, in spite of the vigorous attack on

the multiple-choice test in recent years, test makers still

25

see it as the most versatile and effective of the various
types of objective test items.3 Therefore it was decided
that a multiple-choice test, if constructed properly, would
yield an instrument that was adequate for the study.

The original twenty-item test was administered to thirty
fourth-grade pupils from a population that was similar in
age, grade'and science background to the experimental group.
The stimulus at the normal rate was presented to the pupils,
and following the presentation, the test was administered as
a post-test. Following the giving of the test, the test was
subjected to an item analysis to determine the difficulty
and discrimination power of each question. According to
Nunnally, the questions for the comprehension post-test
should have had a difficulty level (percentage of total giv-
ing an incorrect response) of 20 to 80 per cent and a discrim-
ination index of 35 per cent (percentage difference between
the top 25 per cent and the bottom 25 per cent). The larger
the difference, the better the item.LF (See Appendix C for
the results of the analysis for discrimination and difficulty
index of each question.)

Since five of the original twenty test items did not
meet the discrimination and difficulty criteria for inclusion

they were eliminated. Although three of the fifteen items

 

3Clinton I. Chase, Measurement for Educational Evalp—
ation. (Reading, Massachusetts: Addison-wesley Publishing

CT, 1971.), p. 110.

#Jum C. Nunnally, Educational Measurement and Evalu-
ation. (New York: McGraw-Hill Book Co., 1964), p. l§2.

26
did not meet the criteria for difficulty, they were used as
part of the test in an effort to reduce the possibility of
creating frustration for pupils who might otherwise have.
missed most or all of the questions.

Horrocks and Schoonover commented on content validity:
"The content must be relevant to the purpose of the measure-
ment; the items selected must be representative, sufficient-
ly complete, uncontaminated with other content, and at the
appropriate level of difficulty."5 Thorndike and Hagan de-
scribed content validity in this manner:

The problem of appraising content validity is
closely parallel to the problem of preparing the
blueprint for a test..., and then building a test
to match the blueprint. A teacher’s own test has
content validity to the extent that a wise and
thoughtful analysis of objectives has been made in
the blueprint, and care, skill and ingenuity have
been exercised in building the test items to match
the blueprint. A standardized test may be shown
to have validity for a particular school or a
particular curriculum insofar as the content of
that test corresponds to and represents the objec6
tives accepted in that school or that curriculum.

In the present study the objective of the comprehension
test was to determine the degree to which the pupils partic-
ipating in the study comprehended the subject matter contained
in the videotape, "The Simple Machine: an Inclined Plane."

After viewing the videotape, four fourth-grade teachers

and the developer constructed the questions used on the

 

5John E. Horrocks and Thelma I. Schoonover, Measurement
for Teachers. (Columbus, Ohio: Charles E. MerriII PuEIIsE-
ing Co., 1968), p. 66

6Robert L. Thorndike and Elizabeth Hagan, Measurement

and Evaluation in Ps cholo and Education. (New YorE: John
Wiley and Sons, Inc., 1969;, p. 164.

27
comprehension test. According to the teachers, the diffi-
culty of the test was appropriate for fourth-grade pupils
in terms of readability and vocabulary. Their judgment was
substantiated by the difficulty index of the item analysis.
The data in Appendix C show that none of the final fifteen
items was unreasonably difficult.

Consequently, the content validity of the test was deemed
satisfactory for the material in this study since the objec-
tives of the test were based upon the content of the video-
taped program used as the treatment for subjects in the

study and the appropriate difficulty level was present.
7

Using Hoyt's Estimate of Reliability Formula, a reli-
ability analysis was performed on the comprehension test.
The results are reported in Table 1. For the purpose of
analysis the subjects' scores on the comprehension test were

determined by the number of correct answers.

Table 1. Reliability Analysis of the Comprehension Test.

 

 

 

Source of Degrees of Sum of

Variance Freedom Squares Vapiance Reliability
Examinees 79 52.50 .664 .8375
Items 14 22.68 1.620

Remainder 1106 299.49 .109

Total 1199 374.67

 

 

7J. P. Guilford, Psychometic Methods. (New York:
McGraw-Hill Book Co., 1954), pp. 383-385.

28

According to Nunnally, reliability coefficients for
examinations should be at least as high as .75 and preferably
higher than .85. The test was acceptable because the
reliability was above the .75 level and was near the .85

level.

Pre-Test

The test used to asSess the knowledge of the subject
prior to treatment was developed by making an alternative
form of the post-test. The stem or options of each question

in the post-test was changed to develop the alternate test.

Procedures

The data were gathered by the experimenter with the
cooperation of the teachers and principals of the partici-
pating schools.

Prior to gathering the data, the researcher met with the
school principal and the fourth-grade science teachers to
acquaint the teachers with the nature of the stimulus mate-
rial and the data collecting instruments.

The subjects participating in the study viewed the
videotape in a mobile classroom adjacent to the building in
which the subjects were housed. This room was equipped with
one teacher's desk, two tables and ten individual armed
chairs. A Sony U-matic VP-1200 video cassette machine was
used to play the videotapes. In order to insure the optimum
viewing conditions, two seventeenainch Sony Trinitron moni-
tors were used for individuals receiving the treatment. The

approximate average viewing distance from the screen was

29

seven feet and the most extreme viewing angle for any pupil
was 45 degrees from the center of the screen.

The subjects received the treatment in accordance with
a pre-planned schedule that enabled the data to be collected
in one school in one day. The schedules were developed in
cooperation with the teachers to accommodate the pupils'
class schedules and the treatment they were to receive.

If the subjects were a group to be given the pre-test,
they were asked to take a test prior to the television
program. (See Appendix D for pre-test and instruction.)

The subjects were then asked to listen for a tone on the
television. Following the tone the videotape program was
presented. After which, the subjects were given the compre-
hension test. (See Appendix E.) After the instructions

were read by the examiner, the subjects were allowed suffi-
cient time to complete the comprehension test. The tests
were collected after all pupils had completed the test.

This procedure was repeated for each of the groups in accord-

ance with their speech compression rate.

Statistical Hypotheses
To test the effects of time compression of a visual
and aural (television) presentation on comprehension of
subject matter by elementary school pupils, the following
hypotheses were generated and tested:
Null Hypothesis I--There will be no difference
between mean comprehension scores of subjects
viewing a videotaped program at the normal

oral reading rate and those viewing 20, 40
and 60 per cent time-compressed versions.

BO

Alternate Hypothesis I--There will be a significant
difference between mean comprehension scores
of subjects viewing a videotaped program at
the normal oral reading rate and those viewing
20,40 and 60 per cent time-compressed versions.
The major difference will occur at the 60
per cent level.

Null Hypothesis II-—There will be no significant
difference in the post- -test scores of subjects
taking a pro-test and those not taking the
pre-test.

Alternate Hypothesis II--There will be a significant
difference in the post-test scores of subjects

taking.a pre-test and those not taking the
pre-test.

Summary
A sample population of eighty fourth-grade pupils was

randomly assigned to eight treatment groups. The treatment
groups were classified by compression levels of 0, 20, 40
and 60 per cent and pre-test or no pre-test. Each treatment
group contained ten subjects. All groups received the same
content message at different rates of compression. The
information sources were in the form of a three-fourths inch
videotape.

A pre-test (See Appendix D) was given to one sub-group.
Then, following the presentation each of the subjects was
given a comprehension test. The questions with four responses
each were duplicated and given to each subject for his com-
pletion. .These tests were scored and a raw score, the number
correct out of fifteen questions, was compiled for each
subject in the experiment.

An analysis of variance was used to determine if there

was a significant difference in the comprehension scores

31
for pupils viewing a videotaped program at the normal oral
reading rate compared to comprehension scores of pupils
viewing 20, 40 and 60 per cent time-compressed versions.
The analysis of variance was also used to determine if there
was a significant difference in the comprehension scores
of pupils taking a pre-test and those not taking the pre-

test a

CHAPTER IV

ANALYSIS OF RESULTS

Introduction
The research hypotheses of this study were tested using
the analysis of variance of the comprehension test scores.
The comprehension test scores were usedas the dependent
variable. The independent variables were the four levels
of compression and the taking or not taking of a pre-test.
All the hypotheses were tested at the .05 alpha level with

the appropriate degrees of freedom.

Analysis of Data
The first analysis was to determine the effects of time

compression of a visual and aural (videotape) presentation
on comprehension of subject matter by elementary school
pupils. The second analysis was to determine if there was
a significant difference in post-test comprehension scores
of pupils taking a pre-test and pupils not taking a pre-
test. The total number of items answered correctly out of
a possible fifteen was the score used in the analysis. See
Table 2 for a summary of the analysis of variance for the

comprehension scores.

32

33

Table 2. Analysis of Variance for Comprehension Scores.

'v—

 

 

 

Source of Variance D.f. Mean Squares F-value
Word Rate 3 26.2124 . 3.2725*
‘ Pre-test/No Pre-test 1 10.5124 1.2114

 

 

*SigniTicant at or above the .05 IeveIO

Word Rate

The testable hypotheses for the effect of word compres-

sion rate are as follows:

Null Hypothesis I--There will be no difference
between mean comprehension scores of subjects
viewing a videotaped program.at the normal
oral reading rate and those viewing 20, 40
and 60 per cent time-compressed versions.

Alternate Hypothesis I--There will be a significant
difference between mean comprehension scores
of subjects viewing a videotaped program at
the normal oral reading rate and those viewing
20, 40 and 60 per cent time-compressed versions.

The analysis of variance of the comprehension test

means (see Table 3) yielded and F-value of 3.2725 which was
significant at the .05 alpha level. This indicated that
there was a significant difference in the comprehension
scores of subjects viewing a videotaped program at the
normal oral reading rate and those viewing 20, 40 and 60
per cent time-compressed versions. Therefore, the null
hypothesis was rejected and the alternate hypothesis

accepted..

34

 

 

 

Table 3. Mean Comprehension Scores for Each Word Rate.
Word_Rate ,pN Meap___
0% Compression (127 wpm) 20 9.3000
20% Compression (154 wpm) 20 8.8500
40% Compression (206 wpm) 20 9.3000
60% Compression (309 wpm) 20 6.9000

 

Analysis of Comprehension between Specific Treatments
In order to determine specifically at what point com-
prehension changed significantly, a Duncan's Multiple-Range

Testl was applied to the results of the analysis of variance.

 

 

 

Table 4. Comparison of Comprehension by Treatment Through
the Duncan's Multiple-Range Test.
Difference *MinImum Range
Groups Between Meaps Difference
Group 1 vs Group 2 .45 1.79
Group 1 vs Group 3 O 1.79
Group 1 ' vs Group 4 2.40 1.88*
Group 3 vs Group 2 .45 1.88
Group 2 vs Group 4 2.55 1.79*
Group 3 vs Group 4 2.40 1.94’:<

 

*SignifIcant at the .05 level

 

1James L. Bruning and B. L. Kintz, Computational Hand-
book of Statistics. (Glenview, Illinois: ‘Scott, Foresman
and Co., 1968), p. 115.

35

The mean for each group, the derived standard error of
the means and the minimum range differences were used in
this calculation of the Duncan's Multiple-Range Test. The
test indicated that there was a significant difference at
the .05 level in the comprehension scores between the 60
per cent compression group and the 0, 20, and 40 per cent

compression groups.

Pre-test

The testable hypotheses for the effect of a pre-test are

as follows:

Null Hypothesis II--There will be no significant
difference in the post-test scores of subjects
taking a pre-test and those not taking the

Alternate Hypothesis II--There will be a significant
difference in the post-test scores of subjects
taking a pre-test and those not taking the

The analysis of variance of the comprehension test

means (see Table 4) yielded an F-ratio of 1.2113 which was
not significant at the .05 alpha level. This indicated that
there was no significant difference in the comprehension
scores of subjects taking a pre-test and those not taking

the pre-test. Therefore, the null hypothesis was retained.

36

Table 5. Mean Comprehension Scores for
Pre-test/No Pre-test Groups.

 

 

 

 

Pre-test N Mean

Yes 40 8.2250

N0 40 8.9500
Summary

The hypotheses were tested through the analysis of
variance. .The Duncan's Multiple-Range Test was used to de-
termine between which compression rates there was a signif-
icant difference in comprehension scores of subjects. The
.05 alpha level of confidence was used in teeting the two
hypotheses and the Duncan's test for significance. A dis-
cussion of the findings and their implications are found in

Chapter V.

CHAPTER V

SUMMARY AND CONCLUSIONS

The purpose of this study was to investigate the effects
of time compression of a videotape presentation on the com-
prehension of science subject matter by fourth-grade ele-
mentary school pupils. The major concern in the study was
to determine if the comprehension of pupils receiving com-
pressed videotape information differed significantly compared
to pupils receiving the same information by videotape at the
normal speaking rate. Another concern was to analyze the
post-test scores of pupils taking a pre-test and those not
taking the pre-test to determine if there was a significant
difference.

The initial research in the area of speech compression
was conducted in 1940 by Harry Goldstein at Columbia Univer-
sity, NewYork.1 In Goldstein’s research, however, no mechan-
ical device was used to increase the rates of speech. In-
stead, he used human speakers who were trained to read the
passages at the desired rates. The majority of the research

using compressed speech has been conducted since Grant

 

1Harry Goldstein, Reading and Listening Comprehension
at V ious Controlled Rates. eachers ollege ontri ut one
to Education #82I, Board 0? Publications. (New York: Teach-

ers College, Columbia University, 1940).
37

38
Fairbanks, W. L. Everitt and R. P. Jaeger introduced the
mechanical sampling method of compressing speech. They
demonstrated this method at the 1953 National Convention of
Othe Institute of Radio Engineers in New York City.2 Research

3

by Foulke, Amster, Nolan and Bixler; Fairbanks, Guttman and

" Foulke and Sticht;5 and Foulke6 has shown that the

Miron;
comprehension of compressed messages does not vary signif-
icantly until the word rate approachs or exceeds the 275
word per minute level.

In the review of related literature the studies using
vaudio compression with accompanying visuals were primarily
interested in determining if the addition of visual stimuli
increased the comprehension of compressed auditory infor-
mation. These studies did show that the combination of audio
and visuals in presentations was superior to visual only or
audio only at high rates of speed. The intention was not to
compare the comprehension scores of subjects receiving an
audiovisual presentation at the normal rate with subjects

receiving time-compressed versions to establish a threshold

at which there was a significant difference in the scores.

 

2Fairbanks and others, "Method for Time or Frequency
Compression."

3Foulke and others, "Comprehension of Rapid Speech by
the Blind."

"Fairbanks and others, "Effects of Time Compression."

5Foulke and Sticht, "Listening Rate Preferences."

6Foulke, "Listening Comprehension as a Function of
Word Rate."

39

In order to test the comprehension of a videotaped pas-
sage by elementary pupils, a sample population of eighty
elementary pupils was randomly assigned to the eight treat-
ment groups. The subjects were grouped by the four levels
of word rate, 0, 20, 40 and 60 per cent compression, and the
taking or not taking of a pre-test. Each of the ten subjects
within four groups took a pre-test, watched the videotaped 3
program of the appropriate per cent of compression and was
given the comprehension test following the videotape. The
other four groups did not take the pre-test but watched
the videotaped program of the appropriate per cent of com-
pression and were given the comprehension test following
the videotape.

The videotape, "The Inclined Plane: A Simple Machine,"
served as the stimulus material for the study. The audio
for the videotape was originally recorded at 127 words per
minute. In addition to the normal or 0 per cent compression
word rate, the audio was compressed to 154, 206 and 309
words per minute. The video presented was relative to the
audio, and it was also compressed by video editing the various
segments to correspond to the audio. However, no video seg-
ments were totally eliminated.

The analysis of variance was employed in order to deter-
mine the effect of a time-compressed videotaped presentation
on the comprehension of subject matter of elementary pupils
and to determine if there was a significant difference in
post-test scores of pupils taking and not taking a pro-test.

The Duncan MUltiple-Range Test was used to determine between

40
which compression rates there was a significant difference in
comprehension scores of subjects. The .05 level of confidence

was used to test the two major hypotheses for significance.

Findings and Conclusions

The analysis of the data concerning the comprehension
scores of pupils viewing a videotaped program supported the
following findings and conclusions:

Finding 1. A significant difference was found in the
pupils' scores on the comprehension test when comparing the
0, 20, 40 and 60 per cent compression rates. The signifi-
cance was when the 60 per cent (309 words per minute) com-
pression rate was compared to the other three (0, 20 and 40
per cent compression) rates of presentation.

Conclusion 1. The results of videotape compression was
similar to audio only compression, and it may be concluded
that a compression rate of 40 per cent or a word per minute
rate of less than 275 may be used without any significant
difference in mean post-test comprehension scores.

Finding 2. No significant difference was found in the
post-test scores of subjects taking a pro-test and those not
taking a pre-test.

Conclusion 2. The administering of a pre-test to fourth-
grade pupils did not sensitize pupils to subject matter of a
compressed videotape presentation and did not invalidate or

significantly affect the post-test scores.

41
Discussion of Results

The data analysis indicated that the administering of a
pro-test made no significant difference in the mean post-
test scores of subjects when used in conjunction with a
compressed videotaped presentation as the stimulus material.

No significant difference was found when the mean post-
test scores of pupils viewing the 0, 20 and 40 per cent com-
pressed videotapes were analyzed. A significant difference
was found when the 60 per cent compression rate was compared
to the 0, 20 and 40 per cent compression rates. This finding
is consistent with the theoretical position taken in this
paper in that the results of audio and video compression of
information was very similar to that of audio only compres-
sion since the information pr0cessing system was a single-
channel system and was selective at any given time among the
different cues.

Other areas of research that might be considered in
future studies similar to this one would be in the areas of

subliminal and statistoscopic vision.

Implications for Education
The following implications, drawn from this study, are

worth considering:

1. In information transmission systems which are ex-
tremely expensive or in situations where time limitations
are great, a compression of up to 40 per cent of televised
instructional presentations can effectively be used with

science materials for fourth-grade pupils.

42

2. Teachers may uSe a pre-test to assess the compre-
hension of science material of fourth-grade pupils before
viewing a videotape without significantly affecting the
post-test scores.

3. It is obvious from previous research and from the
findings of this study that more appropriate applications
(could be made of videotape and audiotape compression to save

learning time.

Suggestions for Further Research

Following are suggestions for possible further study
of the use of compressed videotapes:

l. The present study might be replicated with different
subject matter and at different grade levels. Although the
results of this study are quite conclusive for the population
that was involved, replication would likely serve to substan-
tiate the findings and broaden their generalizability.

2. Additional research might be conducted using com-
pression of videotaped stimulus material that relies less
on audio information and more on video information. This
would provide some basis for deciding whether the compression
of video cues of highly visual presentations can be success-
fully accomplished while maintaining comprehension at an
acceptable level.

.3. Further study might be done to investigate the
use of compressed videotapes in combination with normal
classroom instructional activities. The present study did

not use any classroom activity to prepare the students for

43

the viewing of the videotape presentation nor was there any
follow-up activity.

4. A further suggestion is that this study might be
greplicated using a larger experimental population. Since
this study was restricted to a small sample, a larger sample
might increase the statistical accuracy of group measurements.

5. Further research might be done with a greater com-
pression of images in order to study the interaction of audio
and video compression where extreme video compression is

used.

BIBLIOGRAPHY

BIBLIOGRAPHY

Anderton, Ray L. "The Effect of a Time-Compressed Tape-Slide
Instructional Program upon the Learner." CRCR News-
letter, III(December, 1969), 4.

Benz, Carlton R. "Effects of Time-Compressed Speech upon
the Comprehension of a Visually Oriented Television
Lecture." Dissertation Abstracts, XXXII(May, 1972),

6579-A.

Boyle, Virginia A. "Effects of Variations in Visual Stim-
ulation of Listening Comprehension." CRCR Newsletter,
III(December, 1969), l.

Broadbent, D. E. Perception and Communication. New York:
Pergamon Press, 1958.

Bruning, James L. and Kintz, B. L. Computational Handbook
of Statistics. Glenview, Illinois: Scott, Foresman

and Co., 1968.

 

Chase, Clinton I. Measurement for Educational Evaluation.
Reading, Massachusetts: Addison-Wesley Publishing Co.,

1974.

Cherry, E. C. "Some Experiments on the Recognition of Speech
with One and Two Ears." Journal of the Acoustical
Society of America, XXV(1953), 975-79.

Coronet Films, Inc. Simple Machines:- Inclined Planes.
Chicago: Coronet Films, Inc., 1960.

Fairbanks, Grant; Everitt, W. L.; and Jaeger, R. P. "Method
for Time or Frequency Compression--Expression of Speech."
Transaction of the Institute of Radio Engineers Profes-
sional Group on Audio, AU 2, 1954, 7-12.

Fairbanks, Grant; Guttman, Newman; and Miron, Murry S.
"The Effects of Time Compression upon the Comprehension
of Connected Speech." Journal of Speech and Hearing
Disorders, XXII(March, 1959), 10919.

Ferguson, George A. Statistical Analysis in Psychology and
Education. New York: McGraw-Hill Book Co., 1971.

 

44

45

Foulke, Emerson. "Listening Comprehension as a Function of
Word Rate." The Journal of Communication, XVIII
(September, 1968); 198-206.

Foulke, Emerson and Sticht, Thomas. "Listening Rate Pref-
erences of College Students for Literary Material of
Moderate Difficulty." The Journal of Auditory Research,
VI(1966), 397-401.

Foulke, Emerson; Amster, C. H.; Nolan, C. Y.; and Bixler,
T. H. "The Comprehension of Rapid Speech by the Blind."
Exceptional Children, XIX(November, 1962), 134-41.

Goldstein, Harry. Reading and Listening Comprehension at
Various Controlled Rates. Teachers College Contri-
butions to Education, #821. New York: Teachers College,
Columbia University, 1940.

Guilford, J. P. Psycometric Methods. New York: McGraw—
Hill Book Co., 1954.

Hoban, C. F. and VanOrmer, E. B. "Instructional Film Re-
search." University Park: Pennsylvania State Univer-
sity (SDC 269-7-19), 1950.

Horrocks, John E. and Schoonover, Thelma I. Measurement
for Teachers. Columbus: Charles E. Merrill Publishing
Co., 1968.

 

Loper, James L. "An Experimental Study of Some Effects of
Time Compression upon the Comprehension and Retention
of a Visually Au ented Television Speech." Dissertatipp
Abstracts, XXVII June, 1967), 4370-A.

Miller, Neal E. "Graphic Communication and the Crisis in
Education." AV Communication Review, V(February, 1957),
Special Supplement.

Nelson, H. E.; Moll, R.; and Jaspen, N. Comparison of the
Audio and Video Elements of Instructional Films.
Special Devices Center, Technical Report 269-7-18.
Port Washington, N. Y.: Special Devices Center, 1950.

Nunnally, Jum C. Educational Measurement and Evaluation.
New York: McGraw-Hill Book Co., 1964.

Parker, John P. "The Effect of Varying Degrees of Compres-
sion in a 16mm Sound Motion Picture upon Information Recall."
Dissertation Abstracts, XXXII(December, 1971), 29l8-A.

Perry, Thomas K. "The Effects upon the Learner of a Com-
pressed Slide-Audio Tape Presentation Experienced in a
Learning Carrel as Measured by a Recall and Application
Test." Unpublished doctoral dissertation, Michigan
State University, 1970.

46

Severin, Werner. "Another Look at Cue Summation." AV
Communications Review, XV(Fall, 1967), 233-45.

Thorndike, Robert L. and Hagan, Elizabeth. Measurement and
Evaluation in Psychology and Education. New York:
John Wiley and'Sons, Inc., 1969.

Travers, Robert M. W. "The Transmission of Information to
Human Receivers." AV Communications Review, XII

(Winter. 1964), 373-85.

Van Mondfrans, A. P. An Investigation of the Interaction
Between the Level of Meaningfulness and Redundancy in
the antent ofIthe Stimulus Material and the Mode of
Presentation of the Stimulus Material. Master's thesis,
University of Utah, 1963. (Typewritten)

 

Vincent, W. 8.; Ash, P.; and Greenhill, L. P. Relationship
of Length and Fact Frequency to Effectiveness of
IEBtructional Motion Pictures. Special Devices Center,
Technical Report 269-7-7. Port Washington, N. Y.:
Special Devices Center, 1950.

Watts, M. W., Jr. "Using Compressed Speech to Teach Instruc-
tional Techniques to Air Force Officers." Presentation
to the Second Louisville Conference on Rate and/or
Frequency Controlled Speech, (October, 1969).

Woodcock, Richard W. and Clark, Charlotte R. "Comprehension
of a Narrative Passage by Elementary School Children
as a Function of Listening Rate, Retention Period, and
I. Q." The Journal of Communication, XVIII(September,
1968 ) , 259-71 0

APPENDIX A

STIMULUS MATERIAL SCRIPT

STIMULUS MATERIAL SCRIPT

THE INCLINED PLANE: A SIMPLE MACHINE

All around us are machines that help us
do work. It is easy to recognize a
bicycle, a machine that carries people,
but it is a simple machine which helps

a bicycle go from the street to the side-
walk. The ramp slopes and any slope is
an inclined plane. Scientists call an in-
clined plane a simple machine because it
helps us do work. In the caSe of the
bicycle, the slope helps to raise the
bicycle to the height of the curb. If
the bicycle had to be raised that height
without the simple machine of the slope,

this work would be much harder.

It takes a force of ten pounds to lift

a ten-pound weight straight up. If, in-
stead of lifting the weight straight up,
we use an inclined plane, it takes less

force. With this inclined plane it only

takes nine pounds of force to lift the

47

48
ten-pound weight. The inclined plane

made the work a little easier.

we repeat this demonstration, but with

a flatter slope. Using the flatter slope,
the force needed to move the weight is cut
to about five pounds. But to raise the
weight the same height as before, we have
to move it further. Each time the slope
is flattened, it is necessary to pull for
a longer distance, but less force is re-

quired.

Inclined planes, trading distance for
force, can make work easier. On this
basis, do you understand why a road build-
er makes a highway wind back and forth
along a mountainside? You have to travel
farther to go up the mountain, but if the
road were built straight up the side of
the mountain, few cars would have the

power to climb it.

Steps are a kind of inclined plane. To
use them you travel a greater distance,
but it is much easier than if you had to
climb straight up without the inclined

plane.

49
A circular stairway is a kind of inclined
plane known as a "screw". If we were to
unwrap the threads of a screw, we would
find an ordinary inclined plane that

trades distance for force.

There are inclined planes in the model
screws we see. The threads on one of the
model screws has a steeper slope than
those on the other. Which takes more
force to turn? Which travels farther
around to go the same idstance? Let us
unwind the thread which represents the
ridges that spiral around a screw. The
one with the steeper slope requires four
revolutions; the one with the flatter

slope requires six revolutions.

Another form of an inclined plane that
helps us in our work is the wedge; it is
a simple machine that helps spread things
apart. When a man splits a piece of wood
the wedge multiplies the force of his
hammer and separates the wood. The axe

is another wedge, as is the knife.

Remember that in the inclined plane we

trade distance for force.

APPENDIX B

PILOT STUDY COMPREHENSION TEST

PILOT STUDY COMPREHENSION TEST

Instructigns to Subjects

Please be seated wherever you choose and make yourself
comfortable. If you do not have a pencil or pen hold up
your hand.

You are about to see a short television program. Do not
attempt to take any notes, just relax and watch and listen to
the program. If the person talking appears to be speaking
more rapidly than normal this is the way it is supposed to
be and nothing is wrong.

It will now be necessary for you to take a test. You
may guess if you are not sure about an answer. Be sure to
fill in the upper right corner with your name, the name of
your homeroom teacher and this number _____,

Thank you very much for your time and cooperation. This

section is dismissed and we will return to your room.

50

l.

PILOT STUDY COMPREHENSION TEST

Remember in the inclined plane we trade

a. distance for force
b. force for distance
c. height for force

d. distance for height

Which simple machine helps to spread things apart?

a. wheel
b. wedge
c. hammer
d. screw

A circular stairway is a special kind of inclined plane.
Which of these best describes the circular stairway?

a. road

b. slope
c. screw
d. wedge

Why would a road builder build a road around a hill instead
of straight up the hill?

a. easier to see where you are going
b. requires more force to travel up
0. cheaper to build

d. requires less force to travel up

To gain the advantage 0f having to use less force, we
applied the force over .

a. less distance

b. less height

c. greater distance
d. greater height

What happens to the force required to move a weight up a
slope when the slope is flattened?

a. increased
b. decreased
c. unchanged
d. none of these

51

10.

’ 11.

12.

13.

52

If you raise an object that weighs three pounds without
the use of a simple machine how many pounds of force
would be needed?

a. 1
be. 2
c. 3
d. 6

If you were going to load an object that you could not
lift into a truck, which length of ramp would make the
loading easier?

a. 13 feet
b. 16 feet
0. 19 feet
d. 25 feet

Which of the following is not a form of an inclined plane?

a., wedge
b.‘ screw
0. slide
d. pliers
The inclined plane helps us to make work .

 

a.> better
b. harder
0. longer
d. easier

Which of the screws shown here would go into the wood faster?

a_‘ b c 3

Which of the following would not be an example of an
inclined plane?

a. hammer
b. knife
0. chisel
d. axe

The closer together the threads are on a screw the
it is to turn.

a. harder
b. easier
0. faster
d. slower

53

14. What advantage is there to a long thin wedge over a short
flat wedge?

a. harder to drive into the wood
b. easier to drive into the wood
0. splits the wood faster

d. splits a larger 10g

15. How does increasing the number of times a path winds
around a hill affect your climbing? It makes it

a. harder
b. shorter
c. prettier
d. easier

16. Why is a slope a simple machine? It helps us .

ta. turn a wheel
b. ride a bicycle
0. open a door

d. do work

17. What is the name of a special case of the inclined plane
that helps us travel from one floor of a building to

another?
a. slope
b. elevator
c. stairs
d. wedge
18. What is the name of the simple machine that helps the
bicycle go from the street to the sidewalk?
a. screw 5
b. wheel
0. inclined plane
d. wedge
19. Which of these inclined planes should an object move down
the fastest?
::\\\ .IIT?‘~\S:r \\\\2P\\\ \\::I\\\k
20. The is an inclined plane turned around a center
shaft. '
a. wheel
b. door knob
c. screw
d. wedge

 

APPENDIX C

PILOT STUDY COMPREHENSION TEST
ITEM DIFFICULTY AND DISCRIMINATION INDEX

PILOT STUDY COMPREHENSION TEST
ITEM DIFFICULTY AND DISCRIMINATION INDEX

 

 

Difficulty FDIScrimination
{Ipem _gg Index Index g
1* .83 0.
2 .17 .43
3 .43 .43
4* .83 .14
5 .70 - .71
6 .60 ' .57
7 .60 .43
8 .77 .57
9 .53 .57
10* 0 l7 ' o 29
11 .70 .43
12 .63 .86
13* .83 0
14 .67 .57
15 .53 .57
16 . 53 . 43
17 .50 .43
18 .17 .43
19 .17 .71
20* .87 .14

 

*These items were judged not acceptable because, according to
Nunnally, only items having a difficulty index of 20 to 80
per cent and discrimination index of 35 per cent or above

are acceptable test items. '

54

APPENDIX D

PRE-TEST AND INSTRUCTIONS

PRE-TEST AND INSTRUCTIONS

Instructions to Subjects

Please be seated wherever you choose and make yourself
comfortable. I would like to ask you to take a short test
before we see the television program. Simply do the best
you can on the test without asking any questions. You will
not be penalized for guessing so if you are not sure feel
free to guess. If you do not have a pencil or pen please
hold up your hand.

In the upper right-hand corner of the test please write

your name, your homeroom teacher's name and this number

55

PRE-TEST

Which simple machine helps to spread things apart?

a. axe

b. hammer

c. wheel

d. screwdriver

Which of these inclined planes should an object move down
the slowest?

What is the name of the simple machine that helps the
bicycle go from the street to the sidewalk?

a. screw
b. wheel
0. slope
d. axle

A stairway is a special kind of inclined plane. Which
of these best describes the stairway?

a. road
b. slope
c. screw
d. wedge
Why is an axe a simple machine? It helps us .

 

a. turn a wheel
b. ride a bicycle
c. open a door

d. do work

Which of the following is a form of an inclined plane?

a. wheel
b. hammer
c. slide
d. pliers

56

57

How does decreasing the number of times a path winds
around a hill affect your climbing? It makes it

a. harder

b. shorter,-
c. prettier
d. easier

.If you raise an objeCt that weighs six pounds without
the use of a simple machine how many pounds of force
would be needed?

a. 1
b. 2
c. 3
d. 6

Which of the following would not be an example of an in-
clined plane? .

a. hammer

b. knife
0. chisel
d. axe

What is the name of a special case of the inclined plane
that helps a car travel from one floor of a parking '
building to another? .

a. slope

b. elevator
c. stairs
d. wedge

To gain the advantage of having to use less force, we
applied the force over .

a. less distance

b. less height

0. greater distance
d. greater height

Which of the screws shown here would go into the wood
slower?

58

13. What happens to the force required to move a weight up
a slope when the slope is raised?

a. increased
b. decreased
0. unchanged
d. none of these

14. What disadvantage is there to a short flat wedge over a
long thin wedge? ,

a, harder to drive into the wood
b. easier to drive into the wood
0. splits the wood faster

d. splits a larger log

15. If you were going to load an object that you could not
lift into a truck, which length of ramp would make the
loading harder?

a. 13 feet
b. 16 feet
c. 19 feet

d. 25 feet

APPENDIX E

COMPREHENSION TEST AND INSTRUCTIONS

COMPREHENSION TEST AND INSTRUCTIONS

Instructions to Subjects
You are about to see a short television program. Do not
'attempt to take any notes, just relax and watch and listen to
the program. If the person talking appears to be speaking
more rapidly than normal this is the way it is supposed to be
and nothing is wrong.

It will now be necessary for you to take a test. You
may guess if you are not sure about an answer. Be sure to
fill in the upper right corner with your name, the name of
your homeroom teacher and this number .

Thank you very much for your time and cooperation. This

section is dismissed and we will return to your room.

59

l.

COMPREHENSION TEST

Which simple machine helps to spread things apart?

a.
b.
c.
d.

Which of

wheel
wedge
hammer
screw

these inclined planes should an object move down

the fastest?

A x \ \

What is the name of the simple machine that helps the
bicycle go from the street to the sidewalk?

a.
b.
c.
d.

screw
wheel
inclined plane
wedge

A circular stairway is a special kind of inclined plane.
Which of these best describes the circular stairway?

a. road
b. slope
c. screw
d. wedge
Why is a slope a simple machine? It helps us . .

a.
b.
c.
d.

 

turn a wheel
ride a bicycle
open a door
do work

Which of the following is not a form of an inclined plane?

a.
b.
C.
d.

wedge
screw
slide
pliers

60

61

7. How does increasing the number of times a path winds
, around a hill affect your-climbing? It makes it

a. harder
b. shorter
c. prettier
d. easier

‘8. If you raise an object that weighs three pounds without
the use of a simple machine how many pounds of force
would be needed?

a. l
b. 2
c. 3
d. 6
9. Which of the following would be an example of an inclined
plane?
a. hammer
b. knife
c. 'wheel
d. road

10. 'What is the name of a special case of the inclined plane
that helps us travel from one floor of a building to

another?
a. slope
b. elevator
c. stairs
d. wedge .

11. To gain the advantage of having to use less force, we
applied the force over .

a. less distance

b. less height

c. greater distance
d. greater height

12. Which of the screws shown here would go into the wood
faster?

"7':

 

 

62

13. What happens to the force required to move a weight up
a slope when the slope is flattened?

a. increased
b. decreased
c. unchanged
d. none of these

14. What advantage is there to a long thin wedge over a short
flat wedge?

a. harder to drive into the wood
b. easier to drive into the wood
c. splits the wood faster

d. splits a larger log

15. If you were going to load an object that you could not
lift into a truck, which length of ramp would make the
loading easier?

'a. 13 feet
b. 16 feet
c. 19 feet

'd. 25 feet

"MANNES