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CONSUMER ATI'ITUDES ABOUT OPEN DATING TECHNIQUES FOR
PACKAGED FOODS AND NON-PRESCRIPTION DRUGS
By

Jongkyoung Kim

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree Of

MASTER OF SCIENCE

School of Packaging

1 996

ABSTRACT

CONSUMER A'ITITUDES ABOUT OPEN DATING TECHNIQUES FOR
PACKAGED FOODS AND NON-PRESCRIPTION DRUGS

By

Jongkymmg Kim

The purpose of this study was to reveal consumer attitudes about various open
dating techniques for packaged foods and non-prescription drugs. Two hundred shoppers
were surveyed. Major findings included the following:

1) Open dates and spoilage indicators are valuable consumer information and can
give a marketing advantage, especially for perishable meat and dairy products.

2) On average, female shoppers think that open dates are a more important piece
of information than do males.

3) Almost half responded that they would not serve food after sell-by date.

4) Over two-thirds would not use a non-prescription drug after the expiration
date because of safety concerns.

5) Respondents said that spoilage indicators and “use-by” dates are the most
useful techniques.

6) Reducing confusion through consumer education about open dates and shelf
life of foods and non—prescription drugs will be a very important step to reduce

unnecessary food wastes and health risks.

Copyright by
Jongkyoung Kim
1996

DEDICATION

This thesis is dedicated to my lovely family, whose faith in me and endurance
kept me going in time Of doubt and stress. To Hyunhye, Eunhee and Jongmoo, whose
understanding of this process ensured the successful completion of this study. To my

parents, who encouraged me with endless love.

iv

ACKNOWLEDGMENTS

I am most appreciative of the many people who made this work possible. A very
special thank you is extended to Dr. Diana Twede, major professor and chairman of the
graduate committee, for encouragement in supporting this research, valuable financial
support, and for her patience in editing the thesis. I also wish to express my deeply felt
appreciation to the members of my graduate committee, Dr. Hugh Lockhart, Mr. Joel
Lichty and Dr. Tom Pierson. Their support and inspiration added meaning to this study.
Especially for Dr. Joel Lichty, I am very thankful for his statistical support. His
knowledge and patience was of significant assistance.

I am deeply indebted to Mr. Mike Heintzman and the Kroger company for
providing valuable place and coupons to conduct research. A special thank you to the
two MAP assistants, Adriane E. Mayes and Lauren V. Williams, for completing 200
interviews with patience and sincerity.

To my many fi'iends, especially, Meung-hoon Lee, Jai-neung Kim, Younsuk,
Hojoon, Jaemin, Dongoon and Sangyoon, whose encouragement was incredible. Special
thanks to Hui and Scott, who have encouraged me, mere thanks are not enough.

Finally to my family who deserve thanks for their immeasurable love. How can I

describe this all?

TABLE OF CONTENTS

Page
LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . viii
LIST OF FIGURES . . . . . . . . . . . . . . . xii
CHAPTER I : STATEMENT OF THE PROBLEM . 1
Purpose of the Study . . . 2
Need for the Study 3
Research Questions 4
Methodology 4
Definition of Terms 5
CHAPTER II : REVIEW OF THE LITERATURE . . . . . . . . . . 7
Determining the Shelf Life of Foods . . . . . . . . . . . . . 7
The History of Open Date Studies . . . . . . . . . . . . . 9
Open Dating Techniques . . . . . . . . . . . . 13
Expiration Dating for Non-prescription Drugs. . . . . . . . . . 16
Regulation of Open Shelf Life Dating Techniques . . . . . . . . 18
Summary. . . . . . . . . . . . . . . 22
CHAPTER III : RESEARCH METHODOLOGY . . . . . . . . . . . 23
The Research Questions . . . . . . . . . . . . . . . . . 23
Survey Instrument . . . . . . . . . . . . . . . . . . . 24
Population and Sampling . . . . . . . . . . . . . . . . 26
Data Analysis . . . . . . . . . . . . . . 27
Assumptions and Limitation of the Study . . . . . . . . . . . ‘28
CHAPTER IV : ANALYSIS AND INTERPRETATION OF THE DATA . . . 29
Demographic Data . . . . . . . . . . . . . . . . . . . 30
Gender and Age . . . . . . . . . . . . . . . . 30
Family Size . . . . . . . . . . . . . . . . . 31
Education . . . . . . . . . . . . . . . . . 33
Shopping Frequency . . . . . . . . . . . . . . 33

Page

Income . . . . . . . . . . . . . . . . 34

Shopper Characteristics. . . . . . . . . . . . . . 34

Section 1: Importance of Open Dates . . . . . . . . . . . . 35
Overall Scales . . . . . . . . . . . . . 35

Subscales and Interaction Effects. . . . . . . . . . . 36

Section 2: Unexplained Dates . . . . . . . . . . . . . . . 39
Section 3. Products Past the Date . . . . . . . . . ' . . . . . 43
Comments from Shoppers. . . . . . . . . . . . 46

Section 4. Usefulness of Open Date Techniques . . . . . . . . . 50
Demographic Correlations. . . . . . . . . . . . . 52

CHAPTER V: SUMMARY, CONCLUSIONS AND RECOMMENDATIONS. . 54
Summary of the Results . . . . . . . . . . . . . . . . . 54
Conclusions and Implications . . . . . . . . . . . . . . . . 55
Recommendations for Further Study . . . . . . . . . . . . . 57
APPENDIX A: SURVEY INSTRUMENT . . . . . . . . . . . . . 59
APPENDD( B: CONSUMER COMMENTS . . . . . . . . . . . . 65
APPENDD( C: INTERACTION EFFECTS . . . . . . . . . . . . . 67
APPENDIX D: LENGTH OF INTERVIEW TIME. . . . . . . . . . . 73
BIBLIOGRAPHY.....................74

LIST OF TABLES

Table

1. Distribution of Participants by Gender

2. Distribution of Participants by Age .

3. Distribution of Participants by the Number of Adults in Households .

4. Distribution of Participants by the Number of Children in Households .
5. Distribution of Participants by the Family Characteristics

6. Distribution of Participants by Level of Education .

7. Distribution of Participants by Shopping Frequency .

8. Distribution of Participants by Level of Income

9. Distribution of Participants by Shoppers’ Characteristics.

10. The Results of Section 1: Shoppers’ Perception of Importance of Open Date

on Food and Non-prescription Drugs.
11. Rotated Factor Matrix (V arimax) for Section 1

12. Shoppers’ Perception of Importance of Open Date on Food and
Non—prescriptionDrugs. . . . . . . . . . . ..

13. AN OVA of Shoppers by Gender 1n Section 1: “Shopper’ s Perceptions
toward the Importance of Open Dates.” . . .

14. Results of the Descriptive Analysis of Shoppers by Gender on Question 1:
“Importance of Open Date on Food and Non-prescription Drugs.” . .

15. Results of Section 2: Shoppers’ Explanations about Unexplained Dates
(ValidPercent).

viii

Page
30
3 1

31

32
33
33
34

34

36

37

38

38

38

40

Table Page

16. Shoppers’ Shelf-life Perception on Perishable Foods afier
Sell-byDate......................44

17. Shoppers’ Expected Shelf Life of the Foods after “Sell-by” Date
(ValidPercentofResponse) ................44

 

18. Results of Sub-Question 2: “Will Shoppers Use a Food any time
after the Date (Sell-by or Use-by Date) marked on Package?”
(Valid Percent of Response). . . . . . . . . . . . . . . . 46

 

19. Shopper Belief Statements with the Highest Frequency -
“Will Shoppers Use a Perishable Foods any time after Sell-By
marked on Package?” (Valid Percent of Response) . . . . . . . . . 47

20. Shopper Belief Statements with the Highest Frequency -
“Will Shoppers Use a Perishable Foods any time after Use-By
marked on Package?” (Valid Percent of Response) . . . . . . . . . 48

21. Shopper Belief Statements with the Highest Frequency -
“Will Shoppers Use a Semi-Perishable Foods any time after Use-By
marked on Package?” (Valid Percent of Response) . . . . . . . . . 48

22. Shopper Belief Statements with the Highest Frequency -
“Will Shoppers Use a Shelf-Stable Foods any time after Use-by
marked on Package?” (Valid Percent of Response) . . . . . . . . . 49

23. Shopper Belief Statements with the Highest Frequency —
“Will Shoppers Use a Non-prescription Drugs any time after
Expiration Date marked on Package?” (Valid Percent of Response) . . . . 50

24. The Results of Section 4. Shoppers’ Perception of Usefulness
ofOpenDateTechniques.... 5...1

25. Shoppers’ Perception of Usefulness of Open Date Techniques for
eachFoodCategory...... ..........52

26. ANOVA of Consumer’s Shopping Frequency on Q0301:
“Shopper’s Perception after Sell-by Date.”. . . . . . . . . . . . 67

27. Results of Descriptive Analysis by Consumer’s Shopping Frequency on Q0301:
“Consumer Perception after Sell-by Date.” . . . . . 67

Table Page

28. ANOVA of Shoppers by Level of Distance on Q0601:

“Shopper’s Preference on Date Packaged for Perishable Foods.” . . . . . 67
29. Results of the Descriptive Analysis of Shoppers by Level of Distance on Q0601:
“Shopper’s Preference on Date Packaged for Perishable Foods.” . . . . . 68

30. ANOVA of Shoppers by Gender on Q0604:
“Shopper’s Preference on Smilage Indicators for Perishable Foods.” . . . 68

31. Results of the Descriptive Analysis of Shoppers by Gender on Q0604:
“Shopper’s Preference on Smilage Indicators for Perishable Foods.” . . . 68

 

32. AN OVA of Shoppers by Type of Shoppers on Q0604:
“Shopper’s Preference on Smilgge Indicators for Perishable Foods.” . . . 68

33. Results of the Descriptive Analysis of Shoppers by Type of Shoppers on Q0604:
“Shopper’s Preference on Smilgge Indicators for Perishable Foods.” . . . 69

34. ANOVA of Shoppers by Age on Q0604:
“Shopper’s Preference on Smilage Indicators for Perishable Foods.” . . . 69

35. Results of the Descriptive Analysis of Shoppers by Age on Q0604:
“Shopper’s Preference on Spoilgge Indicators for Perishable Foods.” . . . 69

36. ANOVA of Shoppers by Distance on Q0902:
“Shopper’s Preference on Sell-by Dates for Semi-perishable Foods.” . . . 69

37. Results of the Descriptive Analysis of Shoppers by Distance on Q0902:
“Shopper’s Preference on Sell-by Dates for Semi-perishable Foods.” . . . 70

38. ANOVA of Shoppers by Education on Q0903:
“Shopper’s Preference on Use-by Date for Semi-perishable F oods.”. . . . 70

39. Results of the Descriptive Analysis of Shoppers by Education on Q0903:
“Shopper’s Preference on Use-by Dates for Semi-perishable F oods” . . . 70

40. ANOVA of Number of Adults on Q1001:
“Shopper’s Preference on Semi-mishable Foods after Use-by Date.” . . . 70

41. Results of Descriptive Analysis by Number of Adults on Q1001:
“Shopper’s Perception on Semi-grishable Foods after Use-by Date.” . . . 71

Table

42.

43.

44.

45.

46.

47.

AN OVA of Shoppers by Number of Adults on Q1301:
“Shopper’s Perception on Shelf-stable Foods after Use-by Date”.

Results of the Descriptive Analysis by Number of Adults on Q1301:

“Shopper’s Perception on Shelf-stable Foods after Use-by Date”.

AN OVA of Shoppers by Level of Children on Q1301:

“Shopper’s Perception on Shelf-stable Foods after Use-by Date.” .

Results of Descriptive Analysis by Number of Adults on Q1301:

“Shopper’s Perception on Shelf-stable Foog after Use-by Date.” .

AN OVA of Shoppers by Shopping Frequency on Q1301:
“Shopper’s Perception on Self-stable Foog afier Use-by Date.” .

Results of Descriptive Analysis by Shopping Frequency on Q1301:
“Shopper’s Perception on Self-stable Foods; afier Use-by Date.” .

Page

71

71

71

72

72

72

LIST OF FIGURES

Page
Figure 1. Results of Section 2: Shoppers’ Explanations about
Unexplained Dates (Valid Percent) . . . . . . . . . . . . . . . 42

CHAPTER I

STATEMENT OF THE PROBLEM

The ability to satisfy consumers’ demands for quality and freshness is a strategic
advantage in today’s increasingly competitive food and non-prescription drug retail
markets. Consumer demands related to quality continue to grow, providing an
opportunity for manufacturers to develop better product processing, packaging and
distribution technology. Improved packaging systems ensure that food is
.microbiologically sound, make it easy to handle, retain sensory characteristics of food,
and convey useful information to consumer. Advanced packaging systems also provide
that the non-prescription drug packaging has clear instruction, tamper evident and child
resistant features. Packaging plays a vital role in maintaining the quality of products.

The quality of packaged foods and drugs depends on their freshness. Likewise,
consumers’ perceptions of quality depend on perceived freshness. Foods that are not
fresh may even be a safety risk, and pharmaceuticals that are not fresh may lose emcacy.
Thus, providing adequate information about the freshness of these products is very
important to both consumers and manufacturers.

Consumers’ perceptions of the fi'eshness of products should be enhanced by

providing efi‘ective information on the package. For food and pharmaceutical

manufacturers, effective and clear information about the fi'eshness of their products can
be a powerful marketing tool.

From the viewpoint of consumers, there are several ways to identify the
“freshness” of food products, for instance, visual appearance, smell, Open date, etc.. For
non-prescription drugs, however, the freshness can only be indicated by the expiration
date. The prime purpose of open Shelf-life dating is to inform the consumer about the
shelf-life of the product. The proper open dating on the packages gives very useful

information and helps consumers make informed purchase decisions.

We of theLStudv

The purpose of this study was to provide an assessment of open date usefulness
and understanding, as perceived by shoppers. An open date is a date which is displayed
on the package in a legible, easily readable form (Labuza 1982). To achieve this purpose,
a survey was administered. It was designed to achieve five goals related to the shoppers’
attitudes on open dates, which are as follows:

1. To analyze consumer demands for open date information on various packaged
foods and pharmaceuticals with difledng shelf-life characteristics, including perishable,
semi-perishable, and shelf-stable products.

2. To determine consumer awareness and understanding of the open date systems.

3. To investigate whether demographic variables afl‘ect shoppers’ perceptions
about open dates and Shelf life.

4. To predict the marketing effects of providing effective open date information.

 

5. To identify needs for consumer education regarding the shelf life of food and

non-prescription drug products.

Need for the Stu_dy
More than a decade ago, the Office of Technology Assessment (1979)
conducted a nationwide survey of consumers to determine their attitude about open date
information, usefulness and understanding Of dates, and preference among dates.
However, there has been little in the way of consumer’ education about open dates on
packages.

A recent survey (Consumers Rgte Packagm' g Traits 1995) supports the need for
more research and consumer education. More than four-fifths of the surveyed households
indicated that they would like more information about open dates relative to product
usage. They point out that it is dificult to figure out when a product goes bad because
the current open dates are used in difi‘erent ways.

Not only is this study necessary, it is long overdue. Tremendous improvemert in
food processing, distribution and packaging technologies have led to an enormous change
in shoppers’ life styles. Consumers demand more information on package labels now.
The nutritional labeling law that went into effect on May 8, 1994 seems to have satisfied
the Shoppers’ need for the nutritional information. This now appears on all food

packaging and labeling, and is both informative and effective at attracting consumers.

 

 

 

ie‘

No investigation or survey into shoppers’ perceptions about expiration dates on
non-prescription drug packages was found in any of the literature. But it can be assumed
that there is also great confusion about expiration dates on non—prescription drugs.

There is an Obvious need for consumer education and research in the area of
perceived food and drug Shelf life. This study aims to identify specific concerns with

respect to open dates on packages.

Research Questions

The research questions posed in this study were based on consumer perceptions
about open dates on packages. Responses were sought to the following four research
questions:

1. How important is a date when shoppers are deciding to buy food or non-
prescription drugs?

2. How do shoppers interpret a date without any explanation on the different
kinds
of foods and non-prescription drugs?

3. How do shoppers perceive a date after sell-by, use-by, or expiration date?

4. What is the most useful type of open date for shoppers?

Methodology

The first step in conducting the study was to review the literature. The literature

revealed very few studies concerning open dating techniques on food packages and the

effect on shoppers’ buying decisions. There was no literature about shoppers’ perception
about expiration dates on non-prescription drugs. Therefore, the review of literature
underscores the need for this study. The literature review is presented in Chapter II.

As the literature was reviewed, a survey was developed and refined. The
interview method for data collection was chosen. The researcher and two trained
assistants conducted individual interviews with a random sample of 200 shoppers.
Chapter III contains a detailed discussion of the procedures followed in conducting the

survey.

Definition of Terms

Although there were difi‘erent definitions of terms in the literature, the following
. definitions were used for purposes of this study.

Qpe_n date: a date on a can or package of food that gives the consumer an
indication of when a product was packed or should be sold or used.

Shelf life: the length of time that a product in a container, will remain in a salable
or acceptable condition under specified conditions of storage.

Date of manufacture: the date on which the product becomes the product as
described.

Date packaged: the day, month, and year the product was processed or
packaged for retail sale.

Sell-by date: the last date a product should be sold in order to allow a

“reasonable” length of time for consumer use.

Best-if-used-bmm_e(use-by date, recommended last consumption date,
expiration date): the date after which the food or drug is no longer at its most
acceptable level of quality.

An expiraftion daLte ( for dggg): the date to assure that “a drug product meets
applicable standards of identity, strength, quality, and purity at the time of use” (FDA
1993,92)

Combingtion m: a date providing both of date information such as a sell-by
and best-if-used-by combination.

Spoil_age Indicator ( Time Temperature Indicatog, TI'IS): a simple, inexpensive

 

device that can show an easily measurable, time and temperature-dependent change that
reflects the full or partial temperature history of the food product to which it is attached

. (Taoukis 1991).

An UnexpLained Date: a date code marked on the package needs to be explained

or written clearer.

CHAPTER II

REVIEW OF THE LITERATURE

While public concern about the safety and fi'eshness of foods and non-prescription
drugs has markedly grown, relatively little research on open dating systems has been
conducted since the early 19805. This discussion of the literature focuses on shoppers’
perceptions of open dating systems. This chapter is divided into the following six topics:
_ determining the shelf life of foods, the history of open date studies, open dating
techniques, expiration dating for non-prescription drugs, government regulation of open

dating systems, and a summary.

Determining the Shelf Life of Foods
The shelf life of foods and drugs varies, and shelf life information helps the
consumer to purchase foods of high enough quality, safety and nutrition to meet his or her
needs. Therefore, establishing a fairly accurate shelf life for a particular food or non-
prescription drugs is critical. Incorrect shelf life can potentially bring about legal, safety
or financial problems while failing to meet consumer expectation (Ellis 1994).
Gnanasekharan (1993) describes three general methods to predict the shelf life of

a packaged food. Traditionally, Shelf life evaluation consisted of extended or accelerated

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storage studies. While extended shelf life studies might take years to complete depending
on products, accelerated shelf life tests attempt to reduce testing time by accelerating
deterioration mechanisms through exposure to abusive environmental conditions like
high temperature or humidity. Mathematical modeling of the shelf life of packaged foods
predicts shelf life considering food degradation mechanisms, environmental factors on
packaged food, and properties of packaging materials.

The general criteria to establish a date will depend on what the date is meant to
imply. For example, a sell-by date should mean that there is still high quality life for a
reasonable time period after the date. Ofice of Technology Assessment (1979) explains
three alternative criteria for setting up an open shelf life date: sensory quality, nutrient
loss and perishability of products.

Sensory quality is the most important characteristic for consumers and processors
alike, especially for shelf-stable products. Manufacturers define their own quality
standards through elaborate product development studies. Consumer reaction is the key
to sensory quality standards.

Another measure of shelf life could be the loss of a certain percentage of a critical
nutrient, for example, vitamin C. This factor would be much easier to measure than
overall quality since it can be analyzed accurately and rapidly in the laboratory. However,
it is dificult to determine levels, below which a loss in nutrients is of significance to the
overall product quality.

Finally, some states in the United States with open shelf life dating requirements

use perishability time categories to establish an open shelf-life date such as perishable

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foods, semi-perishable foods, and non-perishable foods. Perishable foods have a short
Shelf life, usually less than 30 days. Semi-perishable foods can be defined as those foods
with a shelf life of between 1 and 6 months. Non-perishable or shelf-stable foods have a

Shelf life of more than 6 months (US Congress 1979).

The History of M Date Studies
An open date on a food product is defined as a legible and easily readable date

which is displayed on the package. Open dates are one of the most important pieces of
information on food labels. The Food Marketing Institute’s 1990 trends survey shows
that 72 percent of consumers read labels for expiration dates (Mueller 1991). A survey by
the Ofiice of Technology Assessment (OTA) in 197 8 formd that 91 percent of consumers

- think that the open date is the most important piece of information on the package label
for fresh meat and 50 percent think that it is important for frozen vegetables (US
Congress 1979). In 1979, the US Food and Drug Administration (FDA) also conducted a
survey, and three-quarters of the consumers responded that they had used an open date in
making their purchase decision (Open Shelf-life Dating of Food 1981).

The OTA survey (1979) found that the highest consumer preference among single
dates and combination dates were “last day used” and “sell-by and use-by date”
respectively. Consumers want to have clear and accurate usage information fiom the
package.

However, the Open dating system cannot guarantee either the acceptability or the

safety of the product. This is because many factors, for example, temperature abuse

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during storage and distribution afiects shelf life beyond the control of those who select
the date printed on the packages. For this reason, the idea that the open dating
enforcement Should be conducted by food processors and consumers rather than through
federal or state agencies has been generally accepted. There is no universally accepted
open dating system for food in the United States, but federal agencies provide some
regulations and guidelines, particularly for perishable food items (Open Shelf-life Dalti_ng
W 1981).

There was a comprehensive study discussing the inclusion of “sell-by” dates in the
new German regulations on labeling foodstuffs to apply to all pro-packaged foods.
Jagerhuber (1982) insists that “sell-by” dates should be realistic and achieved after the
relevant products have been subjected to tests simulating actual storage conditions, either
~ in-house, or by external examination. He also points out that produce which has reached
the market after the “sell-by” date Should be marked either with “not for consumption” or
“significantly diminished in value.”

It is noticed that much food is thrown away because its “sell-by” date has passed,
even though the food may still be quite edible. It is suggested that difierent keeping times
should be indicated for storage in deep-freeze, under refiigeration and at room
temperature (Shelf-Life Dales replace with. .. 1977).

The OTA (1979) points out that there is little evidence to support or to negate the
contention that there is a direct relationship between open shelf-life dating and the actual
freshness of food products when they are sold. Nevertheless, consumers often try to buy

“younger” and “fiesher” foods from supermarkets referring to the open date on the

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packages. The OTA survey also found that 62 percent of the consumers try to get the
freshest food products possible. This consumer behavior destroys the “first in-first out”
basis display system in supermarkets (An Anlysis of Consumer Demgnds.w 1981).
This is one of the reasons why the consumers must be educated about the open dating
system.

An FDA nationwide survey found that 43 percent of all consumers do not know
that the date stamped on milk is the date by which it should be sold (pull date) and 62
percent think it should be the date by which milk should be used (use date) (Labuza
1982). This assumption has led to consumer rejection of slightly older packages with
good quality, and eventually has caused a loss of merchandise and destroyed stock
rotation at retail stores. Because many consumers do not seem to know that a sell-by date
' includes a period of home storage during which the product remains at acceptable quality,
they are confused as to the safety of food products bearing sell-by or pull dates, especially
if they are purchased near or on the date itself (Open Shelf-life Dating of Food 1981).

The recent survey conducted by Packagm' g Digest (Consumers Rate Packagm’ g
Mtg 1995) found that more than four-fifths of the surveyed households indicated that
they would like more open date information relative to product usage. 25 percent
believed that a fresh product should be thrown out on the day of expiration, and 60
percent said it should be tossed within three days. For refrigerated foods, however, there
were only 14 percent who said it should be discarded within three days. With processed

foods, consumers are willing to continue using a product well beyond its expiration date.

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There have been some controversies about the usefulness and the benefits of the
open dating system among governmental agencies, manufacturers and consumers. The
Ministry of Agriculture in England concluded that it is dificult to accept the views
expressed by manufacturers that open date marking might result in substantial price rises.
Especially for the perishable products, the difliculties will be greatest for manufacturers,
“but the potential advantages are also greatest” (Ministry of Agriculture, Fisheries and
Food 1972).

Open shelf-life date marking of perishable food and pharmaceuticals can be a
marketing service and competitive advantage (Escher 1984). He insists that invisible
hazards and imperfect knowledge and information about foodbome risks make food
safety an explosive issue, that can disrupt markets and cause substantial economic losses
- for everyone, from farm input suppliers to consumers.

But if open dating can be a strategic advantage for the marketers of perishable
products, there is some disagreement about benefits for the producers of longer shelf-life
products such as carbonated beverages. Some marketing investigators worry that
increasing consumers’ demands for open dating will reach to forming strict federal
regulation, which will affect manufacturers, and will eventually increase product price
(Horton 1994). This controversy began with the Pepsi-Cola Company with the idea that
the open dating system can be part of a marketing strategy. Aspartame, which is used as
an artificial sweetener, significantly loses its sweetness after 12 to 14 weeks although
there is some question as to whether the loss of sweetness of aspartame means end of the

product’s shelf life (The Dating Game 1994).

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Open Datinglechniques

The purpose of open dating is to give the consumer a date which will provide
information about the expected shelf life and quality of the product if it has been properly
stored (Open Shelf-life Dating of Food 1981). There are various open dating techniques,
depending upon the product characteristics and preference of manufacturers and
consumers. The following are several types of open dating systems currently employed
(FAQ/WHO 1992 and US Congress 1979):

1. Date of manufacture is the date on which the product becomes the product as
described.

2. A date packaggg pack date) is the day, month, and year the product was
processed or packaged for retail sale.

3. A sell-by date is the last date a product should be sold in order to allow a
“reasonable” length of time for consumer use.

4. Date of minimum durability (best-if-sold-by date) is the date which signifies
the end of the period under any stated storage conditions during which the product will
remain fully marketable and will retain any specific qualities for which tacit or express
claims have been made. However, beyond the date the product may still be perfectly
satisfactory.

5. A best-ifised-by date(use-by date, recommended last consumption date) is the

date after which food is no longer at its most acceptable level of quality.

thea

ontl

com

reco.
reco:
be It

shou

that 1
gm;
temp
Mini
“Sell
Am

(17:

Whlc]

flucu

Math

l4

6. An expiration date is the date that a drug product is expected to remain within
the approved shelf life specification provided that it is stored under the conditions defined
on the label in the proposed containers and closure (USP 23 1995).

7. Combinaiion dates may be also used such as a sell-by and best-if-used-by
combination.

While many documents discussed open dating recommendations for each product,
recommendations vary by authors. For fi'ozen foods, for example, Childers ( 1982)
recommends the “Best-if-used-by” date, providing accurate determination of shelf life can
be made. National Food Processors Association (NF PA) (1989) suggests that there
should be two categories of refrigerated foods according to perishability and safety
hazard. For the group A foods, which is highly perishable, packaged, processed foods
* that must be refiigerated for safety reasons, “Must-be-used-by” is recommended. For the
group B foods, the products intended to be refiigerated but have no safety hazard if
temperature abused, “U se-by”, “Sell-by” or other proper date marking is recommended.
Ministry of Agriculture, Fisheries and Food of the United Kingdom (1972) recommended
“Sell-by” date because of the dificulties to measure the exact duration of storage.
According to the United Kingdom Association of Frozen Food Producers (UKAF F P)
(1978), appropriate storage information should also provide for ‘star’ (*) marked fieezer,
which indicate storage periods at -12 °C (**) and -6°C(*).

One of the major environmental factors for perishable foods is temperature
fluctuation. As temperature increases, loss of quality increases following the Arrhenius

relationship, simple kinetics mathematical model (Labuza 1982). Ifthe products are

the ap

on the

combi

retort
recom
be ma
shoult
harm
that m
5011;)
lempe
Minis
“Sell-l
ACCor
(1978;

“hich

fluctua

relatio,

l4

6. An expiram date is the date that a drug product is expected to remain within
the approved shelf life specification provided that it is stored under the conditions defined
on the label in the proposed containers and closure (USP 23 1995).

7. Comb'magm dates may be also used such as a sell-by and best-if-used—by
combination.

While many documents discussed open dating recommendations for each product,
recommendations vary by authors. For fi'ozen foods, for example, Childers (1982)
recommends the “Best-if-used—by” date, providing accurate determination of shelf life can
be made. National Food Processors Association (NF PA) (1989) suggests that there
should be two categories of refrigerated foods according to perishability and safety
hazard. For the group A foods, which is highly perishable, packaged, processed foods
’ that must be refiigerated for safety reasons, “Must-be-used-by” is recommended. For the
group B foods, the products intended to be refi‘igerated but have no safety hazard if
temperature abused, “U se-by”, “Sell-by” or other proper date marking is recommended.
Ministry of Agriculture, Fisheries and Food of the United Kingdom (1972) recommended
“Sell-by” date because of the dificulties to measure the exact duration of storage.
According to the United Kingdom Association of Frozen Food Producers (UKAFFP)
(1978), appropriate storage information should also provide for ‘star’ (*) marked freezer,
which indicate storage periods at -12 °C C") and -6°C(*).

One of the major environmental factors for perishable foods is temperature
fluctuation. As temperature increases, loss of quality increases following the Arrhenius

relationship, simple kinetics mathematical model (Labuza 1982). Ifthe products are

tempera‘
useless t
introduc
conditic
potentiz
various
(1985)
harvest
history

elemer

prodtlc
CXpose
reason
Some '

bm th.
“idel:
Open .

Produ

delen

15

temperature abused in distribution channel and retail stores, open dates on packages are
useless (T aoukis 1991). For this reason, time-temperature indicators (TITS) have been
introduced as alternatives to an open date and have been used to monitor temperature
condition of food products throughout distribution. Any distribution channel has great
potential for temperature abuse, to reduce the quality and shelf life of foods because of
various criteria such as environmental conditions, packaging, processing, etc. Jeffery
(1985) notices that a typical food product is handled and moved at least 17 times from
harvest and manufacture to point of consumption. Thus, there is a need to monitor the
history of time-temperature exposure of product, which may be the most important
element for quality control during distribution flow (Fields 1985).

Campbell (1985) defined TTI as a device which may be affixed to the outside of a
' product package to provide evidence of the thermal history to which the product has been
exposed. There are, as yet, limited commercial applications of TTIS for a number of
reasons: high cost, unreliability of some T'l'Is, lack of consistency and reproducibility of
some TITS, and so on (IF ST 1993). In 1982, at least 60 such TTIs have been patented,
but there are still none in widespread use (F arquhar, 1982).

Nevertheless, Taoukis (1991) stresses that suitable and economical TTIs will be
widely used for consumer products in the near future and they can be combined with the
open date to give more information to the consumer about fi'eshness and stability of the
products.

A recent consumer survey conducted by Sherlock (1992) was undertaken to

determine whether the concept of the use of a consumer readable shelf-life T'I'I tag (CT)

in cor
to fol
of C01
Sherl

pros

ofdrt

to ten
condi

date 1

US C
meets
(Natit

Ei‘idet

16

in conjunction with open shelf life dating would be a useful practice for the dairy industry
to follow. Success of the application of the TIT used as CT implementation is a function
of consumers’ education about food spoilage and the dependability of the CT technology.

Sherlock also suggests that consumer education would be a necessary part of this type of

program.

Expirgtion Mr Non-prescription Dru_g§

United States Pharmacopeia (USP BM 18 1995, p. 1963) defines the shelf life
of drugs (“Expiration Dating Period”) as “the time interval that a drug product is expected
to remain within the approved shelf life specification provided that it is stored under the
conditions defined on the label in the proposed containers and closure. The expiration
date limits the time during which the article may be dispensed or used.”

The expiration date is determined by appropriate stability testing described in the
US Code of Federal Regulations, Title 21, section 211.166, to assure that “a drug product
meets applicable standards of identity, strength, quality, and purity at the time of use”
(National Archives and Records Administration 1993, 92). Stability testing can provide
evidence on how the quality of a drug substance or drug product varies with time under
the influence of a variety of environmental factors such as temperature, humidity and
light, and enables recommended storage conditions, retest periods, and shelf lives to be
established. There are five criteria for acceptable levels of stability: chemical, physical,

microbiological, therapeutic, and toxicological (USP 23/NF 18 1995).

more c
more it
shelf li
that '11
outer p

Archll

more 1
inform
friendl
(lentil
shall b
and ea
label It
supple
labelir.

Years 1

P1115 a
detelic

1993').

17

It is generally accepted that the need for information to be conveyed by the label is
more crucial for drugs than for food, and the accuracy of the information on the label is
more important. The shelf life dating of drugs is also more tightly regulated than is the
Shelf life dating of foods. For example, the Code of Federal Regulations (CFR) requires
that “the expiration date” must be provided “on the immediate container and also the
outer package, if any, unless it is easily legible through the outer package”( National
Archives and Records Administration 1993, 16).

1 Because the consequences of mislabeling drugs or misreading by consumers are
more likely to be harmful than that of foods, and because the presentation of product
information in an easily readable and understandable form makes it more consumer
fiiendly, especially for elderly consumers, the expiration date should be clearly indicated
‘ (Jenkins 1993). The United States Pharmacopeia (1995) explains that the expiration date
shall be prominently displayed in high contrast to the background or sharply embossed,
and easily understood (e.g., “EXP 6/89,” “Exp.June89,” “Expires 6/89”). However, the
label need not Show an expiration date in the case of “a drug product Or nutritional
supplement packaged in a container that is intended for sale without prescription and the
labeling of which states no dosage limitations, and which is stable for not less than 3
years when stored under the prescribed conditions.”

Drugs are usually kept on the shelf life far longer than are food products. This
puts a special demand on the package design to protect the contents against slow
deterioration and on the package label to convey a realistic expiration date (Jenkins

1993).

dating b
measure
been gr:
retailers
find out
agencie

product

food pa
dating t
”3ng t
approat
Strongl:
feels th
result i]
across 1
benefih

mm the

Depart:

18

Regulation of Open Shelf DEW

There have been many limitations to achieve a universal regulation for Open
dating because any regulations focused on predicted shelf life, rather than a real time
measure of product quality, depending on appropriate storage conditions. There have
been great efl‘orts to keep optimum distribution environments by manufacturers and
retailers, but time-temperature abuse can occur. On the other hand, it is very dificult to
find out whether the packaged foods have gone bad or not. Thus, government regulatory
agencies would not have available the needed methods to determine whether a given
product that is still in date is out of compliance with some quality standard (Fields 1985).

Since the State of Massachusetts issued regulations concerning the open dating of
food packages in 1979, there have been many controversies about regulation of open
' dating technique in the USA. Some state governments have passed laws on open dating,
trying to solve the diverse and often conflicting demands from consumers by various
approaches. Dr. George Michael of Massachusetts Department of Public Health is
strongly in favor of open dating, but he has gotten a bad response from the industry. He
feels that open dating, along with prescribed temperatures and method of storage, would
result in an optimum distribution system. However, even some government oflicials
across the country charged with implementing the law have varying opinions on the
benefits of open dating laws and regulations. The following five telephone interviews
with the government ofi'rcials were summarized by Labuza (1982, 18-21):

Billy Riddle, Assistant Director of Consumer Protection Division, the Georgia

Department of Agriculture, has mixed filling about the problem - he feels open dating has

benefl
of date
years)
wareh

life pr:

eIlforct
When
Price.
aware .
and Mt

mandat

Health

time p0

19

benefits for the consumer, especially for perishables and knows consumers are very aware
of dates on food. But he cited the problem of long shelf life for canned food (22 '/2
years). In fact, just because food is in-date does not assure good quality (distribution and
warehouse conditions are more important). He feels that Open dating for some long shelf
life products may just increase prices.

Oregon has passed laws on open dating in 1973. Carl Farmer, of the Food and
Dairy Division said that regulations fiom state have been confusing to everyone:
consumers, retailers and manufacturers. Some products are required to have the pack
date, some (with shelf lives less than 30 days) are required to have the pull date. For
fi'esh meat (including poultry) the pack date is the date it is packaged in the supermarket.
He feels the issue is confusing and that it is hard to know what is the best way to
' implement the law - everyone has a difi‘erent idea.

Arizona passed legislation in August, 1974. Through this legislation the state
enforces the voluntary dating of perishable products with a shelf life of less than 60 days.
When the products are overage they must be designated as such and sold at a lowered
price. There were a lot of problems with this legislation at first but now consumers are
aware of it and markets practice good stock rotation. West Horton, the Arizona Weights
and Measures section of the Department of Agriculture and Horticulture, thought that a
mandatory open dating law would work in Arizona.

There is no open dating law or regulations in Arkansas. Bill Teer, of the Arkansas
Health Department feels if open dating were mandatory it would take a lot of personnel

time policing it when there is no problem with the food.

after v
Florid
wastet
anyth'l
of 3 pr

patriot

carry a
have b
beat in
legisla
require
date is

health,

With “1

20

Florida has open dating on milk and all grade A dairy products (expiration date,
after which they are not sold). Dr. George M. Rose of the Division of Inspection of the
Florida Food Grades and Standards Bureau says that it is entirely unnecessary and
wasteful to have required open date on processed food. The pack date does not mean
anything to consumers-they just look for the freshest product. They don’t have that much
of a problem with foods. He says it is hard to educate the public against open dating,
particularly for non-perishables.

Food legislation in many developed countries requires most prepackaged foods to
carry a date of ‘minimum durability’. The procedures to evaluate appropriate shelf lives
have been established mainly by manufacturers. In the United Kingdom, for instance,
‘best before’ date is the most common type of date marking required by current
' legislation to appear on prepackaged foods. Meaningful storage instructions are also
required alongside the best before date if the food is to be enjoyed at its best. ‘Use by’
date is required when the food is highly perishable and has a significant risk to human
health. Selling any food in the UK after its ‘use by’ date is illegal (Ellis 1994).

In Germany, Federal German legislation replaces minimum shelf life marking
with “use by” date marking in effective 1 July, 1993. This legislation declares that
foodstuffs may not be sold after their use by date. However, the German Food Retailers
Association says the new legislation does not clarify which foodstufiis are aflected (IE
by Date Rgplaces -- 1993).

Finding a “significant” loss in quality of foods and non-prescription drugs would

be dificult to measure in a regulatory sense unless the regulators were trained for each

product.
to the se
indicato
Althoug
foods. tl

their use

dating i.

flexibili
time for
uniform

labeling

dates. I
inventc

for cal:

{Ollow
Open d;

OPEncL

21

product. What is needed is a chemical or physical index that changes in a similar manner
to the sensory changes. OTA (1979) expects some type of accurate reliable shelf-life
indicators that could measure reaction rate of food to both temperature and moisture.
Although such indicators can be utilized for shipping fi'ozen food cases or pallets of
foods, they predict that the indicators may never become inexpensive enough to warrant
their use on individual consumer packages.

OTA also suggests three basic legal options for Congress to consider in the open
dating issue: Voluntary System, Mandatory System and Voluntary/Mandatory System.

First, Voluntary System is advantageous because it allows manufacturers
flexibility in determining whether or not to Open date, minimizing the cost and allowing
time for specific research to develop more eflecfive open dating system. However, lack of
' rmiformity in deciding open date techniques, scientific measurements and open date
labeling may cause confusion to all Government, manufacturers and consumers.

Second, Congress could take Mandatory System requiring the use of Specific open
dates. It has advantages because by providing standardized regulations which tightening
inventory control, it can reduce food waste and set higher quality standards and criteria
for calculating open dates.

Finally, Voluntary/Mandatory System is “one in which the Federal Government
develops guidelines, and processors who choose to open date food product are required to
follow these guidelines”. The prime advantage of this system is providing uniformity of
open date for products while individual processors have some flexibility of determining

open dates. However, this may increase costs to government for developing open dates

for ever)

Congres

accompl

and C011:

life after

product.

Consum.

rCplace .

22

for every products and cause time consuming for both Government and industry (US

Congress 1979).

Summary

Based on the review of literature, the following implications are summarized:

1. Consumer education about open dating techniques has not yet been
accomplished.

2. There has been a tremendous confusion by state governments, manufacturers
and consumers about the open dating techniques.

3. There are varying perceptions and measurements of shelf life, including shelf
life after the sell-by date, the effect of temperature abuse, and shelf life variation by
' product. I

4. There is more than one solution for accurate shelf life information and
consumer readable open dating techniques. New technologies like Tl'Is will eventually

replace or coexist with open dates in the future.

and undt
and disc
treatmer

utilized

Pmscrip

of tomC

CHAPTER III

RESEARCH METHODOLOGY

, The purpose of this study was to provide an assessment of open date usefulness
and understanding, as perceived by shoppers. This chapter states the research questions
and discusses the research methodology, survey instrument, population, procedure, and
treatment of the data. This chapter is also an attempt to provide structure that can also be

utilized for futme studies of this subject.

The Research Qaestions

This study was based on four research questions:

1. How important is a date when shoppers are deciding to buy food or non-
prescription drugs?

2. How do shoppers interpret a date without any explanation on difl‘erent kinds
of foods and non-prescription drugs?

3. How do shoppers perceive a date after sell-by, use-by, or expiration date?

4. What is the most useful type of open date for shoppers?

From these four research questions, 16 individual questions were generated to

provide information about shoppers’ perceptions toward open date techniques.

23

 

thesis Ct
inten’ie‘
an OPPO
Program
Unil'ers
order of

Male

Sim-e3:

questior

24

W

The survey instrument was developed by the investigator with input fiom the
thesis committee and feedback from a pilot test, through a number Of drafts. The
interview method was selected for this survey to ensure a good response rate and provide
an opportlmity to answer the respondents’ questions. Two MAP (Minority Apprentice
Program of the College of Agriculture and Natural Resources in Michigan State
University) high school students were hired and trained. The length of the interview and
order of the questionnaire were the most carefully determined in order to limit the
interview time to 10 minutes. The interviews were conducted in July 1995.

The interview began after a brief introduction explaining the purpose of this
survey. The survey questionnaire consisted of 25 questions including 9 demographic
' questions and was divided into five sections (Appendix A):

Section 1: Importance of Open Dates for Shoppers in their Buying Decision.
Included here was in question 1. A number of individual foods and non-prescription
drugs were discussed and 16 samples were chosen considering perishability of products
and availability in supermarkets. A five-point scale was used, ranging fi'om extremely
important (5) to not at all important ( 1).

Section 2: Shoppers’ Understanding of an Unexplained Open Date on a Package.
Question 2 was designed for this section. In this section, respondents were given four
categories of products: perishable, semi-perishable, shelf-stable, and non-prescription.

drugs, and asked how they interpret an unexplained open date for each product.

25

Section 3: Products Past the Date. Shoppers were asked their perceptions of the
shelf-life of a product after the date marked.

The respondents were asked to assess two things in this section:

1) How long would shoppers expect a food to be usable after the sell-by date?

2) Will shoppers use a product (perishable, semi-perishable, shelf stable food, or
non-prescription drugs) any time after the date (sell-by, use-by, or expiration date)
marked on package?

For the first part, open ended questions asking expected usable time of individual
food items in days were used. Second part consisted of question 3, 7, 10, 13 and 15, and
shoppers were asked whether they would use a product after open date or not.
Respondents could present why they would or would not use in the following open ended
‘ questions: 4, 8, 11, 14 and 16.

Section 4: Usefulness of Open Date Techniques. This section included three
question groups (question 6, 9, 12.) to study about consumer preference among the four
open date techniques: date packaged, sell-by, use-by, and spoilage indicators. A five-
point scale was also used in this section, with responses ranging from “(5) extremely
useful” to “(1) not at all useful.”

Section 5: Demographic Backgrormd Information. The researcher assumed that
the consumer awareness and understanding of open dating system might depend upon
various personal, social, and economic factors. Thus, 9 questions were generated,
including sex, age, education, income, family Size, and frequency of shopping, and

whether interviewees were the primary Shoppers in their families.

The
(Lansing. 1
most com
were typic
drugs. Th
representa
area. one '

Tl
July 10 tr
entering :
obtain in
samples
dfimogra
were uor

diSCmsi

26

Population and Mg

The population for the study consisted of shoppers at three Kroger supermarkets
(Lansing, East Lansing and Okemos) in mid-Michigan. Kroger supermarkets, one of the
most common grocery stores in United States, were chosen because target participants
were typical shoppers who usually do grocery shopping for foods and non-prescription
drugs. These three diflerent locations were chosen to get a range of respondents
representative of the regional population. One store location is in a lower-middle income
area, one is in a college town, and the third is in an upper-middle-class suburb.

The data were collected on site from 10 a. m. to 5 p. m. during weekdays between
July 10 to July 27, 1995. The investigator and two trained interviewers approached
entering shoppers and asked for their participation. Although it was almost impossible to
' obtain true representative of the regional population, researcher tried to get the best
samples as close as possible true range of gender and age difl‘erence. Obtaining good
demographic variables such as income, numbers of households, level of education, etc.
were not possible with this survey method. Chapter V explains for the limitations and
discussions about sampling method based on the results.

Approximately 30 percent of the opportrmistic shoppers agreed to the interview,
resulting in 200 interviews. Most interviews took less than 15 minutes to complete, but
varied depending on the shoppers’ interest. For the distribution of participants by
interview time, see Appendix D. Coupons for a free gallon of milk, donated by The
Kroger Company, and an information sheet about Open dating were given to participants

as a sign of appreciation, following the interviews.

analysi
analysi
Cronbe

quesic

115 out
factors
prinei;

loadin

deterrr
be ex;
rests i]
Used 1.
Perfor
Variab
includ

chapte

27

Data Analysis

The Statistical Package for the Social Sciences (SPSS) was used for the data
analysis. Results were obtained by computing analysis of variance (AN OVA), factor
analysis, and simple statistics including means, frequencies and standard deviations.
Cronbach’s alpha and standardized item alpha were used to test the reliability for multiple
questions on a single topic.

Factor analysis was used to confirm relationships among variables for section 1.
Its purpose was to summarize a large number of variables with a smaller number of
factors. The interpretation of factors was then sorted by size so that variables which load
principally on each factor are grouped together, and are listed in descending order of
loading.

Analysis of variance was employed because it was considered appropriate “to
determine whether the difi‘erences among two or more means [were] greater than would
be expected by sampling error alone” (Glass and Hopkins 1984, 324). When AN OVA
tests indicated the existence of significant differences, the Schefl‘e post-hoe tests were
used to determine pairwise difl‘erences. Two-way analysis of variance was also
performed to determine the statistical significance of perceptions by demographic
variable groupings (see Appendix C). Comments fi'om shoppers were summarized and
included in the Appendix B. The results of the data analysis are reported in the next

chapter.

ma}~ irlflr

following
111835138:
1

perceptit

Kroger s

not trul}

and res;

This Ch:

uStd on

mthe Ill

28

Assumption; and Limitation of the Study
Several Assumptions were made regarding the data generated in this study which
may influence the value of the resulting conclusion. This study was limited by the

following factors:

1. Conclusions assume that the survey instrument was valid and reliable. Some
measures of reliability are presented in the results.

2. Answers to the interview questionnaire were assumed to represent valid
perceptions of the shoppers’ own rmderstanding.

3. The results are limited to those persons who shopped and interviewed at three
Kroger supermarkets in Michigan during July 10 through July 27, 1995. The results may
not truly represent the population of US shoppers.

4. The study is delimited to information obtained fi'om a review of the literature

and responses to the survey instrument.

81mm
This chapter consisted of a description of the methodology and implementation of the
study. The research questions, research methodology and development of a survey
instrument were focused. The population, sampling procedures, statistical procedures
used on the data analysis were also included. The results of the data analysis are reported

in the next chapter.

understz

goals:

foodsar

perishat

PCTCEpri

Phamlac

“allied

Piescn'm

CHAPTER IV

ANALYSIS AND INTERPRETATION OF THE DATA

‘ The major purpose of this study was to determine shoppers’ awareness and
understanding of the open dates on packages. The study was designed to accomplish five
goals:

1. To analyze consumer demands for open date information on various packaged
. foods and non-prescription drugs with difi‘ering shelf-life characteristics, including
perishable, semi-perishable and shelf-stable products.

2. To determine consumer awareness and understanding of the Open date systems.

3. To investigate whether demographic characteristics afi‘ect shoppers’
perceptions about open date5 and shelf life.

4. To predict the marketing effects of providing efi‘ective open date information.

5. To identify needs for consumer education regarding the shelf life of food and
pharmaceutical products.

In order to achieve these goals, sixteen survey questions were developed and
analyzed in the following four sections:

1. How important is a date when shoppers are deciding to buy food or non-

prescription drugs?

29

30

2. How do shoppers interpret a date without any explanation on difiemnt kinds
of foods and non-prescription drugs?

3. How do shoppers perceive a date after sell-by, use-by, or expiration date?

4. What is the most usefirl type of open date for shoppers?

Results from these sections will be explored later in this chapter. But first, the

demographics of the respondents will be described.

Demogaphic Data

Listed in Tables 1 through 8 is the demographic information describing the study
participants. The demographic data recorded for shoppers were: gender, age, family size,
educational attainment, fiequency of shopping, annual income, and whether interviewees

' were primary shoppers in their families.

Gender and Age

Table 1 shows that 34.0 percent of the total sample were males and 65.5 percent

were females.

Table 1. Distribution of Participants by Gender.

 

 

Gender Number Percent of Population
Male 68 34.0
Female 131 65.5
Unrecorded 1 0.5

 

 

Total 200 100.0

 

 

31

Table 2 shows that the greatest percentage of participants (26.0%) were 35 to 44
years of age. Three quarters (74.5%) of the participants were over 35 years old. The age

category of lmder 18 years contained only 1 participant.

Table 2. Distribution of Participants by Age.

 

 

 

 

 

Age Group Number Percent of Population
under 18 l 0.5
18-24 15 7.5
25—34 34 17.0
35-44 52 26.0
45-54 38 19.0
55-64 25 12.5
65 or over 34 , 17.0
Unrecorded 1 0.5
Total 200 100.0
‘ Family size

Table 3 shows the number of adults in each participant’s household. The largest
percentage (61.0%) of participants had two adults in their household. The next largest
percentage (22.5%) had only one adult; 16 percent had 3 or more adults in their

household.

Table 3. Distribution of Participants by the Number of Adults in Households.

 

 

Number of Adults Number Percent of Population
in participants’ household
1 45 22.5
2 122 61.0
3 23 1 1.5
4 7 3.5
5 2 1.0
Unrecorded 1 0.5

 

 

Total 200 100.0

 

 

 

32

As shown Table 4, the largest percentage (63%) of participants had no children.

6.5% of participants had more than 2 children.

Table 4. Distribution of Participants by the Number of Children in Households.

 

 

 

 

Number of Children in Number Percent of Population
participants’ household
0 126 63.0
1 25 12.5
2 35 17.5
3 7 3.5
4 4 2.0
25 2 - 1.0
Unrecorded l .5
Total 200 100

 

Based on the data of Table 3 and 4, family characteristics were firrther analyzed.

36 shoppers lived themselves. 126 shoppers had at least one child in their households.
See Table 5.

Table 5. Distribution of Participants by the Family Characteristics.

Status S.
36 163

Children More than 1 No children
73 126

 

 

 

33

Education

Table 6 shows that the greatest percentage (53%) of participants held a Bachelor’s
degree or higher. It is believed that higher educated people were more interested in this

study and were more willing to participate in the interview.

Table 6. Distribution of Participants by Level of Education.

 

 

 

Level of Education Number Percent of Population
Some high school or less 8 4.0
Completed high school 33 16.5
Some college 52 26.0
Bachelor’s degree 51 25.5
Graduate or professional studies 55 27.5
Unrecorded l 0.5
Total 200 100.0

 

 

' Shopping Fraguency
Table 7 shows that the greatest percentage of participants (46.0%) went shopping

once a week and most shoppers (80.0%) shopped once a week or more.

Table 7. Distribution of Participants by Shopping Frequency.

 

 

Shopping Frequency Number Percent of Population
Everyday 18 9.0
More than once a week 51 25.5
Once a week 92 46.0
More than once a month 37 18.5
Once a month 1 .5
Unrecorded 1 5

 

 

Total 200 100.0

 

 

34

Income

Table 8 shows that 34.5 percent of the participants earned between $25,000 and
$49,999 in total household income. Almost half(44%) earned more than $50,000, and

17.5 percent earned less than $25,000.

Table 8. Distribution of Participants by Level of Income.

 

 

 

 

Income Number Percent of Population
< $25,000 35 17.5
$25,000 < < $49,999 69 34.5
$50,000 < < $74,999 59 29.5
> $75,000 29 14.5
Missing 8 4.0
Total 200 100.0

 

, Show Characteristics
Most (85%) participants said that they were the person in the household who

usually did the grocery shopping for their households, as shown in Table 9.

Table 9. Distribution of Participants by Shoppers’ Characteristics.

 

 

Principal Shopper Number Percent of Population
No 27 13.5
Yes 171 85.5
Missing 2 1.0

 

 

Total 200 100.0

 

 

 

35

Section 1: lrnportance of Open Dates
Overall Scales

Respondents were given a list of 15 common grocery items, ranging fiom fiesh
milk to canned food, and were asked to rate the importance of open dates for each
product. Shoppers rated them on the l to 5 scale, where 5 = "extremely importan ." The
15 responses were aggregated to form a multi-item scale indicating overall importance of
dates on products for each shopper.

i Analysis of responses in Section 1 revealed that a date is important for shoppers’
buying decisions. The importance varied from product to product, depending on product
categories.

Using Cronbach’s reliability coeficients, a coemcient alpha and standardized
’ alpha determined the reliability of the multi-item scale. The coefficient alpha of .8834
and standardized item alpha of .8895 at the .05 alpha level indicates respondents were
consistent and the results have a high degree of reliability. The results are shown in Table
10 in order based on the mean importance score.

As shown in Table 10, the respondents indicated that open dates are important in
their shopping decisions (mean for all products = 3.97). For individual items, shoppers
indicated that an open date is the most important for fluid milk products (mean = 4.77).
Dates were considered the least important for flow pizza (mean = 3.05), but it is
important to note that this means most respondents still gave a high importance for the

item.

36

Table 10. The Results of Section 1: Shoppers’ Perception of Importance of Open Date on
Food and Non-prescription Drugs.

 

 

 

 

Variable Mean Std Dev No of valid cases
Fluid milk products 4.77 .75 198
Fresh meat 4.70 .85 198
Cured meats 4.59 .94 194
Eggs 4.45 1.04 198
Cheese 4.36 1.06 199
Packaged lettuce salads 4.20 1.19 172
Bakery items 4.15 1.20 196
Vitamins 4.02 1.26 185
Fresh Pasta 3.86 1.28 167
Non-prescription drugs 3.84 1.41 194
Cereals 3.46 1.33 196
Potato chips 3.44 1.26 183
Ice cream 3.41 1.36 192
Canned Foods 3.09 1.41 195
Frozen pizza 3.05 1.29 177
Overall Mean 3.97 .72 200

 

Reliability Coeflicients 15 items
. Alpha = .8834 Standardized item alpha = .8895
Subscales and Interaction Effects

A factor analysis on the 15 items was performed in order to examnine whether the
shoppers’ perceptions about the importance of the open date can be grouped according to
the perishability of each product. In analyzing the factors of items in Section 1, it was
found that there are significant differences among the three groups. The three groups are
labeled as Group 1, Group 2 and Group 3. The results are shown in Table 11.

The first group represents the most perishable refiigerated foods: dairy products,
eggs and meat. A second group includes foods with a longer shelf-life: fiozen food,
bakery and snack items, packaged salads and cereal. The third group includes shelf-stable

products including canned food, prescription drugs and vitamins.

 

Tat

iGrc
iFlu
ifres
leis
iCur
iChe

Grc

lee

 

 

 

Fro;
lBalr

'C en
iPoti

Gro
il’ita
’Non
C an

5301.
fresh

(Inca

Grou

37

Table 11. Rotated Factor Matrix (V arimax) for Section 1.

 

 

 

Factor 1 Factor 2 Factor 3

Group 1
Fluid milk products .87492 .09161 .10642
fresh meat .83701 .11266 .12740
Eggs .73851 .15082 .25610
Cured meats .72974 .18095 .25617
Cheese .5 8884 .22684 .24229
Group 2
Ice cream .06731 .72785 .16786
Fresh pasta .40951 .68242 .02734
Frozen pizza -.10036 .651 14 .39996
Bakery items .32169 .59722 .09212
Packaged lettuce salads .53030 .56218 .06922
Cereals .09840 .53239 .52205
Potato chips .12088 .52899 .48237
Group 3

' Vitamins .40256 .01816 .72587
Non-prescription drugs .27173 .03799 .71186
Canned foods .01113 .35525 .67876

 

 

It was interesting to note that fresh salads and bakery items are grouped with
semi-perishables, although salads and bakery items are usually considered perishable.
This reason may be that shoppers tend to be concerned and have questions about the
freshness of meats and diary products much more than other products.

The respondents said that open dates are extremely important for the first group
(mean = 4.5783). Open dates are less important for Group 2 (mean = 3.6299) and

Group 3 (mean = 3.6380). Results are shown in Table 12.

 

38

Table 12. Shoppers’ Perception of Importance of Open Date on Food and Non-
prescription Drugs.

 

 

 

Variable Mean Std. Dev. Valid cases
Group 1 4.57 .73 200
Group 2 3.63 .91 200
Group 3 3.64 1.07 199
Overall 3.97 .72 200

 

 

As shown in Table 13, the shoppers’ perceptions in Section 1 were highly related
to their gender. The analysis of variance for the overall scale revealed that there is a

significant difierence between shoppers by gender (Significance = .0057) about the

importance of open dates.

Table 13. AN OVA of Shoppers by Gender in Section 1: “Shopper’s Perceptions toward
, the Importance of Open Dates.”

 

 

 

Source d.f. Mean Square F-Ratio Sig.
Between groups 1 3.9516 7.8196 .0057
Within Groys 197 .5053

 

On average, females rated the importance of open dates significantly higher

(4.0718) than the males (3.7747). See Table 14.

Table 14. Results of the Descriptive Analysis of Shoppers by Gender on Question 1:
“Importance of Open Date on Food and Non-prescription Drugs.”

 

 

 

 

Gender Mean Std Dev Cases
Male 3.7747 .8727 68
Female 4.0718 .6110 131
Total Cases = 200

Missing Cases = 1 or 0.5 Pct.

 

 

39

Section 2: Unexplained Dates
Respondents were asked how they interpret an unexplained open date for four
categories of products: perishable, semi-perishable, shelf-stable, and non-prescription

drugs. All responses are grouped by following 5 types of dates]:

1. Date when the product was manufactured (Date Manufactured).

2. Date when the product was packaged (Date Packaged).

3. Last day it Should be sold (Sell-by date).

4. Last day that it will taste fresh (or remain efiective) (Freshness Date/Expiration
date).

5. Last day that it is safe to consume (U se-by).

Analysis of responses for the Section 2 revealed that responses were not
consistent or predictable. There is a great deal of confusion about unexplained dates
depending on product types. The less perishable the product, the more confusion. Table

15 reports the results.

 

1There are two possible sources of distortion in the unexplained Open date results. The
questions were asked in an open-ended fashion, but the five possible responses were
prompted when the respondent requested assistance; respondents were prompted
approximately 35% of the time. The data may be slightly distorted because the respondents
may have learned to discriminate more after they answered the first question.

 

40

Table 15. Results of Section 2: Shoppers’ Explanations about Unexplained Dates (Valid
Percent).

 

 

 

Explanation Perishables Semi-Perishables Shelf-Stables Drugs
Date Manufactured 4.0 2.0 6.6 7.7
Date Packaged 5.1 9.2 18.3 6.7
Sell-by Date 59.1 51.5 32.5 28.7
Freshness/Exp. Date 15.7 28.1 26.9 20.0
Use-by 16.2 9.2 15.7 36.9
Total 100 100 100 100

 

 

For perishable foods, over half(59.1%) of the respondents assume that an
unexplained date is the last date it should be sold. But almost one-third believe that it is
the last day that it will fresh taste (15.7%) or the last day it is safe (16.2%). This agree
with their perception that dates are more important for perishables.

Half (5 l .5%) also believe that an unexplained date on semi-perishable foods is the
i last date it should be sold. But many (28.1%) believe that it is the last day that the
product will taste flesh, and a few (9.2%) believe that the food is unsafe after the date.

There is even more confusion about an unexplained date on shelf-stable foods.
About one-third (32.5%) believe that it is a sell-by date, one quarter (26.9%) think that it
is the last day the food will taste fresh, and a significant number (15.7%) believe that it is
the last day that the food is safe. Many (24.9%), however, believe that it indicates a
manufacturing or packaging date, which could easily mislead consumers to believe that
very old food (past the date) is relatively fiesh.

Perceptions about non-prescription drugs are no more clear. The largest
percentage (36.9%) of people believe that an unexplained date is the last day that the

product is safe. This is a notable result because most drugs do not become unsafe, but

41

only become ineffective as they age. Yet only 20% of the responses were consistent with
this fact. Many (28.7%) believe that it is the last date that the drug Should be sold. Some
(14.4%) even believe it is the manufacturing or packaging date. Figure 1 presents the

data in a bar chart.

42

 

Valid Percent(%)

 

 

 

 

 

 

 

 

 

 

 

 

 

Perishables

P

Figure 1. Results of Section 2: Shoppers’ Explanations about Unexplained Dates

(Valid Percent)

a .
g
E;
5
rod

uct Category

 

 

Shelf-Stables

 

 

ilDatewhenthepmductwas ‘

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l

manufactured

IDatewhenthoproduetwas

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r

DLastdayttshouidbesold

ILastdaythatitvvilitaste

5 frusMorromaineffoetive)

r
l

l
I
l

ILastdaythatitissafe
consume ~

j.
r

 

 

43

Section 3: Products Past the Date

Section 3 consists of two sub-questions as follows:

1. How long would shoppers expect a food to be usable alter the sell-by date?

2. Will shoppers use a product any time after the date (sell-by, use-by, or
expiration date) marked on package?

First, respondents were asked, for five types of perishable foods, how long after
the sell-by date they expected the food to be usable, assuming that the packages are
unopened and properly refiigerated. Target products were limited to perishable foods
intentionally based on the following assumptions:

1. Sell-by dates for perishable foods are much more important for shoppers to
make a “use/throw out” decision than for longer shelf life foods.

2. Sell-by dates are the most common type for perishable foods in the current
retail market.

Analysis of results reveal that shoppers’ shelf life prediction for a food after the
sell-by date is about five to seven days. However, the responses were extremely
inconsistent.

The aggregate mean of the independent variables in this question is 6.54 days. Of
the five products, respondents predict the longest life for cheese and eggs: 7 days after the
sell-by date; milk for 3 days; orange juice for 5 days; and packaged lettuce salads for 2
days. These are median values; in all cases the mean was 1-4 days longer, with the
highest mean (9.74) for cheese. However, the standard deviations were all larger than the

mean, Showing a large amount of variability in consumer beliefs. Furthermore, the

 

44

standard deviations varied proportionally with the means. The values are reported in

Table 16.

Table 16. Shoppers’ Shelf-life Perception of Perishable Foods after “Sell-by” Date.

 

 

 

Variable Mean Median Std Dev
Cheese 9.74 7 10.69
Eggs 8.28 7 9.09
Milk 4.04 3 4.47
Orange juice 6.04 5 6.34
Packaged lettuce salads 3.73 2 4.45
For Entire Population 6.54 5.1 5.65

 

 

As shown in Table 17, more than 50 percent of shoppers responded they will use
perishable foods between 1 to 7 days after the sell-by date. However, a considerable
percentage of shoppers (20%) believe milk should be thrown out on the sell-by date.

i More than 15 percent of shoppers said that eggs and packaged lettuce salads should be
disposed on the sell-by date. In contrast, more than one-fourth (28.8% and 27.3%) of the
shoppers indicated that cheese and eggs would be still good after 7 days of the sell-by
date. There may be some data distortion due to the fact that many respondents tended to

say “one week” rather than specifying particular day(s).

Table 17. Shoppers’ Expected Shelf Life of the Foods after “Sell-by” Date (Valid
Percent of Response).

 

Products 0 day 1-3 days 4-6 7 days More than 7 Total

 

 

days days
Cheese 8.1 17.7 13.1 32.3 28.8 100
Eggs 15.2 15.2 12.6 29.8 27.3 100
Milk 20.0 38.5 13.5 21.0 7.0 100
Orange juice 9.7 30.1 16.7 29.6 14.0 100
Packaged 17.3 47.4 13.3 14.5 7.5 100

 

lettuce salads

 

45

Shoppers were also asked whether they would use a food any time after the date
(sell-by or use-by date) marked on package. Shoppers’ perceptions about this decision
was strongly affected by the perishability of each product category. Five questions were
used to explore this concept:

Q3: Would you serve food any time after the "sell-by" date?

Q7: Would you use a perishable food after the "use-by" date?

Q10: Would you use a semi-perishable food after the "use-by" date?

Q13: Would you use a shelf stable food after the "use-by" date?

Q15: Would you take a non-prescription drug after the expiration date?

Although the responses varied (e.g. more people would serve food after the sell-by
date than would take a drug after the expiration date), there was a high degree of
‘ consistency among responses. The set of five questions proved a reliable scale at the .05
alpha level, with a reliability coeficient alpha of .7334 and standardized item alpha of
.7302 using Cronbach’s reliability coefficients. This means that shoppers’ responses
were very consistent over the questions.

Almost half (43.7%) of respondents said that they would not serve food after the
"sell-by" date although the foods were unopened and properly stored. This is a significant
finding because the foods should still be usable after the sell-by date.

Over half(56.3%) responded that they would not use a perishable product after
the "use-by" date, assuming that the package was lmOpened and properly stored. It was
also notable that shoppers tended more to avoid using products after the “use-by” date

when products are more perishable. Fewer (41.9%), responded that they would not use a

46

semi-perishable food after the use-by date, assuming that the package was unopened and
properly stored.

Assuming that the package was rmopened and properly stored, it was found that
shoppers responded with the highest afirmative percentage (63.1%), when they were
asked about shelf-stable foods. Shoppers are more likely to use shelf-stable foods after
the "use-by" date than they are to use perishable foods.

However, most shoppers (69.2%) responded that they would not use a non-
prescription drug after the expiration date, assuming that the package was unopened and
properly stored. These findings would seem to indicate that shoppers did not have
suficient knowledge about open dates, but used as their own reference points. The

results are shown in Table 18.

Table 18. Results of Sub-Question 2: “Will shoppers use a food any time after the date
(sell-by or use-by date) marked on package?” (Valid Percent of Response).

 

 

 

Variable Yes No Total
Sell-by(general) 57.0 43.0 100
Use-by(perishable foods) 43.7 56.3 100
Use-by(semi-perishable foods) 58.1 41.9 100
Use—by(shelf-stable foods) 63.1 36.9 100
Expiration date(drugs) 30.8 69.2 100

 

Reliability coefficient alpha = .7334
Standardized item alpha = 7302.

Comments from Show

Open ended questions were provided to analyze the reasons why respondents

would be willing to serve products after a sell-by date or not. 22 percent of showers

 

47

replied that they would not serve perishable foods afier sell-by date because of food safety
reasons while 39.5 percent said that they would serve because they believe the foods are

safe. The results are shown in Table 19.

Table 19. Shopper Belief Statements with the Highest Frequency - “Will Shoppers Use a
Perishable Foods any time after Sell-By marked on Package?” (Valid Percent of

Response).

 

 

 

 

 

 

Statement Percent
No ,
Foods are not safe. 22.0
Foods are not fi'esh any more. 11.5
Date is on there for reason. 9.5
Yes
It won’t hurt, considered to be good after date 39.5
Point of reference (depend on product) 8.5
It could be checked or tested before used it. 7.5

‘ prrice was reduced 1.0
Don’t believe date on package .5
Total 100
Valid cases 200 Missing case 0

As shown in Table 20, 28 percent of the shoppers said they would not
serve perishable foods after a use-by date because of food safety reasons. 18 percent of
respondents assumed that the foods would still be good after use-by date.

As shown Table 21, 26.4 percent of shoppers said that they will serve semi-
perishable foods after use-by date because it would not hurt their health. Only one

shopper responded that he/ she would serve the food if the price was reduced.

 

 

48

Table 20. Shopper Belief Statements with the Highest Frequency - “Will Shoppers Use a
Perishable Foods any time after Use-By marked on Package?” (Valid Percent of

 

 

 

 

Response).

Statement Percent
No

Foods are not safe 28.0
Date is on there for reason. 15.7
Foods are not fresh any more. 12.6
Yes

It won’t hurt, considered to be good after date 18.0
It could be checked or tested 15.2
Point of reference (depend on product) 10.6
Total 100

 

Valid cases 198 Missing cases

Table 21. Shopper Belief Statements with the Highest Frequency - “Will Shoppers Use a
Semi-Perishable Foods any time after Use-By marked on Package?” (Valid Percent of

 

 

 

 

 

. Response).
Statement Percent
No
Foods are not safe 23.4
Date is on there for reason 9.6
Foods are not fi-esh any more. 9.1
Yes
It won’t hurt, considered to be good after date 26.4
It could be checked or tested. 18.3
Point of reference (depend on product) 12.5
Don’t believe date on package. .5
If price was reduced. .5
Total 100

 

Valid cases 197 Missing cases 3

 

 

49

Only 16.5 percent of respondents replied they would not serve a shelf-stable food
after the use-by date because they believe the food is not safe. This was a significantly

small percentage compared to other product categories. Results are shown in Table 22.

Table 22. Shopper Belief Statements with the Highest Frequency - “Will shoppers use a
Shelf-Stable Foods any time after use-by marked on package?” (Valid Percent of

Response).

 

 

 

 

 

Statement Percent

No

Foods are not safe 16.5

Date is on there for reason. 13.2

Foods are not fi'esh. 7.2

Yes

It won’t hurt, considered to be good after date. 28.9

Point of reference (depend on product) 19.1

It could be checked or tested before used it 14.1
' Don’t believe date on package 1.0

Total 100

 

 

Valid cases 194 Missing cases 6

The highest percentage (35.4%) of shoppers replied that they would not take any
non-prescription drugs after expiration date because safety reasons. This finding means
that a significant numbers of shoppers misunderstand the expiration date for drug
packages. They tended to be concerned about possible poisonous efi‘ects of non-

prescription drugs more seriously than foods. See Table 23.

 

50

Table 23. Shopper Belief Statements with the Highest Frequency — “Will shoppers use a
Non-prescription drugs any time after Expiration Date marked on package?” (Valid
Percent of Response).

 

 

 

Statement Percent
No

Drugs are not safe 35.4
Drugs are not efiecfive any more. 25.6
Date is on there for reason. 10.3
Yes

It won’t hurt, considered to be good after date 21.5
Point of reference (depend on product) 5.6
Don’t believe date on package. 1.0
I paid for it, so I would use it. .5
Total 100

 

Valid cases 195 Missing cases 5

Section 4: Usgfifiness of Open Date Techmug

The respondents found all types of open date techniques to be useful. But there
was a difierence in responses regarding different open date techniques. The spoilage
indicators are perceived to be the most usefirl open dating technique although they are not
common in retail stores. The “use-by” date is viewed as more useful than the “sell-by”
date. The open date techniques are perceived as more useful for perishable foods.
Cronbach’s alpha provided the means for evaluating the Section 4 through the
computation of coemcients. The coemcient alpha is .6974 and standardized item alpha is
.7310, so it shows responses were consistent and reliable.

The respondents were asked what kind of open-date system that they think should

be used, for three categories of grocery products, from perishable to shelf-stable. The

 

51

usefulness of four types of systems were judged on a 5-point scale where 1 equals not at
all useful, and 5 equals extremely useful. The four techniques were:

1. Date packaged

2. Sell-by date (best if sold by)

3. Use-by date (best if used by, expiration date)

4. Spoilage indicators (Time Temperature Indicators, TI'Is)2

The relative usefulness was consistent for all three food product categories (mean
= 3.88). With mean of 4.34, Spoilage Indicator are perceived as the most useful open
dating technique. “Date packaged” is the least useful technique among the four (mean =

3.20). See Table 24 for the results.

' Table 24. The Results of Section 4: Shoppers’ Perception of Usefulness of Open Date
Techniques.

 

 

 

 

Variable Mean Std Dev N

Date Packaged 3.20 1.31 199
Sell-by 3.81 .94 199
Use-by 4.17 .89 199
Spoilage Indicators(TI'Is) 4.34 .96 199
Overall 3.88 .67 199

 

The most useful dating technique for perishable foods was perceived to be
spoilage indicators (mean = 4.53). The “use-by” date was the next highest useful date

technique for shoppers (mean = 4.25). The "sell-by" date(mean = 3.91) is perceived to be

 

2Spoilage indicators (Time Temperature Indicators) were described as a device that
"changes its color or shape to let you know whether the product has been exposed to
temperatures or conditions that would make it go bad."

 

52

more useful that the "date packaged.”(mean = 3.24) But all techniques are judged to be

more useful for perishable foods (mean = 3.98), as shown in Table 25.

Table 25. Shoppers’ Perception of Usefulness of Open Date Techniques for each Food
Category.

 

 

 

 

 

 

 

 

Variable Mean Std Dev N
Perishable Foods
Date Packaged 3.24 1.60 199
Sell-by 3.91 1.16 199
Use-by 4.25 1.14 199
Spoilagflndicators (TITS) 4.53 1.11 198
Overall 3.98 .78 199
Semi-perishable Foods
Date Packaged 3.17 1.48 198
Sell-by 3.90 1.14 197
Use-by 4.28 1.05 197
Spoilage Indicators (TTIs) 4.40 1.15 196
Overall 3.94 .75 197
. Shelf stable foods
Date packaged 3.18 1.49 197
Sell-by 3.62 1.21 197
Use-by 4.01 1.19 197
spoilage indicators (TTIs) 4.11 1.40 196
Overall 3.73 .84 197

 

Demographic Correlations

The researcher found some statistically significant differences, but there were few
meaningful findings from different demographics correlations. For example, female
shoppers thought the open date was more important piece of information than do male.
For most cases, the significance was believed to be a statistical accident. There was no
impressive significance with two-way AN OVA tests. Therefore, researcher concluded

that the perception on open date was not much directly related to demographic

 

53

differences. Results from AN OVA (F -ratio and F-value) for each question are

summarized in Appendix C.

CHAPTER V

SUMMARY, CONCLUSIONS AND RECOMMENDATIONS

S of the Results

1. Shoppers feel that an open date is a very important piece of information for
their buying decision for food and non-prescription drugs.

2. Shoppers tend to rate the importance of open dates higher for perishable
. products.

3. The open date information is more important to females than male shoppers.

4. There is great confusion and a variety of interpretations when shoppers find an
unexplained date.

5 . Shoppers are more likely to interpret an unexplained date as a “sell-by” date
for foods although there is more confusion about shelf-stable foods.

6. Significant numbers believe that an unexplained date would be the date
manufactured or date packaged especially for shelf-stable foods.

7. Over one-third of respondents said that an unexplained date would be “the last

day it will taste fi'es ” or “last day that it is safe to consume.”

54

55

8. Considerable numbers of Shoppers misrmderstood the meaning of a “sell-by”
date and believe that a product like milk should be discarded on that date or within 3
days.

9. Almost half responded that they would not serve foods any time after the
“sell-by” date and many express worries about food safety.

10. Shoppers believe that spoilage indicators would be the most useful open
dating technique.

11. Although “sell-by” type of open date techniques are dominant on the current
markets, respondents said that a “use-by” date was more useful than “sell-by” date. “Date
packaged” was the least useful open date technique. This finding was not much different
compared to the earlier study by US Congress in 1979, which found that consumers
prefer “use-by” date to “sell-by” date.

12. There were a few statistically significant demographic correlations. For
example, female shoppers think that open dates are a more important piece of information

than do males.

Conclusions and Implications

The purpose of this study was to learn consumer attitudes about open dating of
packaged food and non-prescription drugs. Given the results of the study, the following
conclusions are apparent:

1. The researcher revealed the fact through the literature review, there are several

difl‘erent recommended open dating techniques which are dependent on various product

56

types, packaging methods, intended shelf life, and so on. Those complicated and unclear
expressions can not only cause consumer confusion, but also marketing disadvantages.
For this reason, there may be an standardized open date needed. In this case, “use-by” is
recommended because it seems to be the simplest and most preferable open date
technique for consumers. Using only “sell-by” date is not recommended since shelf life
judgment after the “sell-by” date is solely the consumer’s responsibility and causes a lot
of confusion among consumers. Ifmanufacturers use “sell-by” date on the package,
recommended storage conditions and maximum usable time after “sell-by” date (use-by
date) should be always specified after the date marked. In this case, combination of “sell-
by” and “use-by” is also recommended since combination can make the terms clear.
Although there are still limitations to the use of technical devices such as spoilage
indicators, due to their high cost, these will provide more usefirl shelf life information to
consumers in the near future.

2. Any open date technique that gives consumers confusion should be eliminated
from the market. Shoppers were confused about an unexplained date. “Sell-by” date
turned out to be a very ambiguous type of open date because many shoppers have no idea
how long after “sell-by” date a product would go bad.

3. There are little evidence that demographic characteristics affect shoppers’
perceptions about open dates. The only notable correlation was that female shoppers
think open dates are more important than do male shoppers.

4. Open dates are a valuable piece of consumer information and can give a

marketing advantage, especially for more perishable products. AS a marketing strategy,

57

marketing and customer service departments can educate consumers about Open date and
shelf life of their products. Although it is still dificult to provide perfectly accurate shelf
life information for shoppers because of the limited technology and cost, a well-organized
information campaign will eventually help to increase the flesh image of products.

5. The results of this study Show that consumer education about open date and
shelf life of foods and non-prescription drugs is an important step to reduce lmnecessary
food waste and health risks. Too much misunderstanding and confusion exist. Even
though similar research was conducted more than a decade ago, there seems to be no
improvement in consumer education about open dates. Shoppers should know that there
is no problem with drinking milk after a “sell-by” date has passed within two days.
Shoppers should also know that there are many factors that can reduce the Shelf life of

products so that they fail to meet the specified shelf life period. Extensive consumer
education may be done by government, manufacturers, retailers, or consumers

themselves.

Recommendations for Further Study
AS a result of the major findings and conclusions drawn fi'om this study, the

researcher ofi‘ers the following recommendations for further study.
1. Although the ultimate beneficiary of the open date is the consumer, the aspects
from federal governments, retailers and manufacturers have not been reflected in this

research. A survey of retailers’ and manufacturers’ perceptions would be valuable for

58

further study. There should be an investigation of the benefits and costs of regulating
open dates in the US.

2. Spoilage indicators (time-temperature indicators) will be the most useful open
date technique in the future. Studies to develop low cost consumer readable spoilage
indicators are needed.

3. Use-by dates require better shelf life evaluation techniques. Research about

standardization and the possible regulation of techniques is recommended.

APPENDICES

APPENDIX A

SURVEY INSTRUMENT

59

APPENDD( A

Interview no.

CONSUMER SURVEY FOR OPEN DATE SYSTEM

Interviewer name

 

 

 

 

 

Date & Time : 07 / / 1995 AM / PM

Location .'

Length of Interview : (minutes)

Hi, my name is , and I am from Michigan State University. We are interviewing shoppers

about the dates marked on packages.
Would you be willing to participate in a lO-minute interview?

Please understand that your participation is completely voluntary. We will not record your name, so
your responses will be anonymous.

Do you have any questions before we start?

If you have any questions, they can be directed to Dr. Diana 'I‘wede, MSU School of Packaging (517)
353-3869.

60

Q 1: Many different foods and non-prescription drugs are marked with dates to help consumers. I
am going to read a list of items that often have dates on them. For each item, please consider how

important a date is when you are deciding to buy it, and give me a number from 1 to 5 rating how
important a date on the item is to you, where l is not at all important and 5 is extremely important.(

Interviewer record scale.)

1 2 3 4 5
not at all extremely
important important

1. Bakery items
2. Canned foods
3. Cereals
4. Cheese

5. Cured meats (for example, lunch meat.)

.0.
ll!
8

7. Fluid milk products (milk, yogurt)

8. Fresh meat

9. Frozen pizza

10. Ice cream

11. Non-prescription drugs (for example, pain relievers.)
12. Packaged lettuce salads

13. Fresh Pasta

l4. Potato chips

15. Vitamins

Q 2: The dates on different foods and non-prescription drugs can have several different meanings.
Sometimes the date is explained on the package, and other times it is not. Considering different kinds
of foods and non-prescription drugg, If you found a date without any explanatiog, what do you think

it would mean? (read through each possible answer if necessary; better do not prompted; write number
on the space provided.)

1. First, for Erishable foods including fluid milk products,
fresh bakery items, fresh meats, fish and poultry, and fresh
fruits and vegetables

2. What about semi-Erishable foods including snack foods,
cheeses, ice cream, some pickled foods, and cured meats

3. And then, for shelf-stable foods including dried legumes,
nuts and grains, many dried-baked foods such as cereals and
pasta, all canned foods, salt, and sugar

4. And finally for non-prescription drug; including pain relievers.
" Read below possible answers if necessary

1. Date when the product was manufactured

2. Date when the product was packaged

3. Last day it should be sold

4. Last day that it will taste fresh(or remain effective)
5. Last day that it is safe to consume

61

Q 3: One of the typical types of date on a food package is a “sell by” or “best if sold by” date.
Would you serve that food any time after the “sell by” date? (Interviewer circle one.)

1. No 2. Yes

Q 4: Why or why not?

 

 

Q 5: The following food items usually have a “sell-by” date on the package. How long would you
expect each of the following products to be usable after the “sell-by” date? Assume that the products
are unogned and properly ref_r_1g' erated. (Interviewer write the expected period at appropriate food

 

 

 

 

items.)
1. Cheese m
2- Eggs m
3. Milk d_ay§
4. Orange juice 4%
5. Packaged lettuce salads d_a)§

 

Q 6: Now I want you to consider what kind of date you think should be marked on different kinds of
foods. Here are four different date systems for packages: (give interviewee card and read through each

definition)

* Deflition at various can date =systems

* A date gacltaged is the day, month, and year the product was processed or packaged
for retail sale.

* A sell-by date(best if sold by) is the last date a product should be sold in order to allow a “reasonable”
length of time for consumer use.

* A use-by date(best if used by date, recommended last consumption date, expiration
date) is the date after which product is no longer at its most acceptable level of

quality.

* A spoilage indicator changes its color or shape to let you know whether the product
has been warmed to temperatures or conditions that would make it go bad.

62

I want you to consider how useful each of date systems would be for each of the categories of food we
talked about earlier. First, for Erishable foods. (for example, fluid milk products, fi'esh bakery items,
fresh meats, fish and poultry, and fresh fiuits and vegetables.) Please give me a number from 1 to 5
indicating how useful you think each of these date systems would be for Erishable foods, where 1 is
not at all useful and 5 is extremely useful. (give examples of perishable foods if necessary; read each
system name and wait for response.)

l——-i—-—l—l--—I

l 2 3 4 5
not at all extremely
usefitl usefitl

_ 1. date packaged

_ 2. sell by(best if sold by)

_ 3. use by(best if used by, expiration date)

_ 4. spoilage indicators

Q 7: Consider now the “use by” date for pgrishable food. Would you use a perishable food after the
“use by” date? Assume the product is uuoEned and properly stored. (Interviewer circle one.)

1. No 2. Yes

Q 8: Why or why not?

 

 

Q 9: Next, for semi-Erishable foods. (for example, snack foods, cheeses, ice cream, some pickled foods,
and cured meats.) Again, give me a number from 1 to 5 indicating how useful you think each of these
date systems would be for semi-perishable foods, where l is not at all useful and 5 is extremely useful.
(give examples of perishable foods if necessary; read each system name and wait for response.)

l-—l——-l—I-—-—I

l 2 3 4 5
not at all extremely
useful useful

_ 1. date packaged

_ 2. sell by(best if sold by)

_ 3. use by(best if used by, expiration date)
_ 4. spoilage indicators

Q 10: Would you use a semi-mrishable food after the “use by” date? Assume the product is
unouned and properly stored. (Interviewer circle one.)

1. No 2. Yes

63

Q 11: Why or why not?

 

 

Q 12: Finally, for shelf-stable foods. (for example, nuts and grains, many dried-baked foods such as
cereals and pasta, all canned foods, salt, and sugar.) Once more, give me a number from 1 to 5
indicating how useful you think each of these date systems would be for shelf-stable foods, where l is
not at all useful and 5 is extremely useful. (give examples of perishable foods ifnecessary; read each
system name and wait for response.)

l----l—-—l——-l——-l

l 2 3 4 5
not at all extremely
usefitl useful

__ 1. date packaged

_ 2. sell by(best if sold by)

_ 3. use by(best if used by, expiration date)

_ 4. spoilage indicators

Q 13: Would you use a shelf-stable food after the “use by” date? Assume the product is unouned
and properly stored.(1nterviewer circle one.)

1. No 2. Yes

Q 14: Why or why not?

 

 

Q 15: The typical type of date system on a non-prescription drug package is an expiration date.
Would you take the drug after the expiration date? Assume the product is unomned and properly
stored. (Interviewer circle one.)

1. No 2. Yes

Q 16: Why or why not?

 

 

* To help me analyze your answers above, PLEASE ANSWER THE FOLLOWING QUESTIONS

ABOUT YOURSELF AND YOUR HOUSEHOLD. Again, please remember that the surveys are
completely anonymous and that your responses cannot be identified.

Interviewer record sex.

17: Male Female

64

18: I am going to read a list of age categories. Please stop me when I reach your age category.
(Interviewer read the list & circle a number.)

1. under 18
2. 18-24

3. 25-34

4. 35-44

5. 45-54

6. 55-64

7. 65 or over

19: How many children 18 years old or younger are there in your household?

 

20: How many adults, INCLUDING YOURSELF, are there in your household? (note: includes adult
children, grandparents or other relatives, and other permanent adult residents; does not include visitors)

 

21: What is the highest level of education that you completed? (Interviewer circle number.)

1. Some high school or less

2. Completed high school

3. Some college

4. Bachelor’s degree

5. Graduate or professional studies

22: I am going to read a list of income categories. Please stop me when I reach yourTOTAL
HOUSEHOLD income category. (note: income before taxes)

1. Less than $25,000
2. 25,000 to 49,000
3. 3 50,000 to 74,999
4. 75,000 or more
23: Are you the person in your household who usually does the grocery shopping?
1. No 2. Yes

24: How often is grocery shopping usually done for your household? (Interviewer circle number. Do
not prompt.)

1. Everyday

2. More than once a week less than everyday

3. Once a week

4. More than once a month less than once a week

25: How far away from this store is your home in minutes?

minutes

 

Thank you for your time and participating this survey!

APPENDD( B

CONSUMER COMMENTS

65

APPENDIX B

Consumer Comments

Consumer comments showed various opinions from respondents’ own point of

view. Following are comments mentioned by interviewees.

M

“The date should be postmarked for ahead for endurance of use.”

“If the taste is OK; use it.”

“The dates there tell you of some importance, so use until that date.”
“The date deals with usage of consumer.”

“It might look OK, but not safe to the digestive system.”

“Better safe than sorry.”

“To me, if it tastes, looks, and smells fresh; it’s flesh.”

“Just follow the date.”

“I don’t eat anything that might possibly have something wrong.”

“I think they give you a lot of latitude on the date.”

“I’m not a risk-taker.”

“Consumer would check to see if it was OK.”

“The date is on there for a reason. But if I still had it, I would use it.”

“Generally they can be used a few days after the date.”

“It depends on the product.”

66

“I don’t know how harmful it would be after the date.”

“I like the maximum freshness.”

“It would be used after the date but not bought.”

“The date should be placed for enough ahead.”

“It usually has spoiled afier sell—by date.”

“I’m not certain it’s safe to use after date.”

I only want or use products that are acceptable or “safe”.”

“If they (store) sell it, I think it’s still edible. I have a lot of faith in big grocery store
chains.”

“1 might get sick; ingredients may have changed (after use-by date)”

I like things to be at the highest quality. I don’t want to take any chances.”

' I don’t trust the date.”

Non-Prescription Drugs

“Drugs are less stable-either they aren’t as eflecfive or they may be toxic.”
“For fear that it (drug) would be harmful.”

“Less efi‘ective and it may be harmful to your health.”

“Drugs change properties (after the date)”

“Health is too important to tamper with.”

APPENDIX C

INTERACTION EFFECTS

67

APPENDD( C

Integction Effects

In order to see whether demographic variables affect on consumer perceptions, the analyses of the
data included an examination of interaction effects. The relationships between and within variable groups
were the focus of the examination. One-way ANOVA test was performed to determine the difierences that
existed. The Post Hoc Multiple comparison procedures (Scheffe test) with significance level .05 were
performed to view which means are significantly difl‘erent from each other. Further analysis
(Crosstabulation statistics and Two way ANOVA) were also performed if there were significant interaction

happened.

As shown in Table 26, q0301 had a significant difierence by consumer’s shopping frequency; the
significance of the F value was .0272.

Table 26. ANOVA of Consumer’s Shopping Frequency on 00301: “Shopper’s Perception after Sell-by
Date.”

 

 

 

Source d.f. Mean Square F-Ratio Sig.
Between goups 3 .7431 3.1186 .0272
Mthin Groups 195 .2383

Total 198

 

The results of multiple range test (Schefl‘e) show that there are significant difference between

' “everyday shoppers” and “once a week shoppers.” “Everyday shoppers” disagrwd to serve a food after the
sell by date more often (mean = 1.2778) than the “once a week shoppers (1.6522).” This indicates that
“everyday shoppers” are concerned more about freshness of foods than others, and that is why they shop
everyday. See Table 27.

Table 27 . Results of Descriptive Analysis by Consumer’s Shopping Frequency on Q0301: “Consumer
Perception alter Sell-by Date.”

 

 

 

 

Frequency Mean Std Dev No. of Cases
Everyday 1.2778 .4609 18

More than once a week 1.5686 .5002 51

Once a week 1.6522 .4789 92

Less than once a week 1.5263 .5060 38

Entire Population 1.5729 .4959 199

Total Cases = 200

Missing Cases = 1 or .5 Pet

There was a significant difference of shoppers by level of distance (significance = .0396) as
shoppers’ perception difiered as to the date packaged for perishable foods. See Table 28.

Table 28. ANOVA of Shoppers by Level of Distance on Q0601: “Shopper’s Preference on Date Packaged
for Perisfible Foods.”

 

 

 

Source d.f. Mean Square F-Ratio Sig
Between groups 2 8.2063 3.2832 .0396
Within Groups 194 2.4995

Total 1 96

 

 

 

 

 

68

As the distance from the store was further, the shoppers preferred the date packaged dating system.
The shortest distance group (shorter than 5 minutes) had a mean of 2.9540, whereas the longest distance
group(Longer than 10 minutes) had a mean of 3.6829. See Table 29.

Table 29. Results of the Descriptive Analysis of Shoppers by Level of Distance on Q0601 : “Shopper’s
Preference on Date Packaged for Perisirflale Foods.”

 

 

 

Distance Mean Std Dev Cases

Shorter than 5 minutes 2.9540 1.6629 87
6 to 10 minutes 3.3768 1.5821 69
Longer than 10 minutes 3.6829 1.3863 41
Total 3.2538 1.5810 197

 

 

There was a significant difference (.0109) of shoppers by gender on q0604 in response to the
preference of the spoilage indicators for perishable foods. See Table 30.

Table 30. ANOVA of Shoppers by Gender on 00604: “Shopper’s Preference on Smilage Indicators for
Perishable Foods.”

 

 

 

Source d.f. Mean Square F-Ratio Sig.
Between groups 1 7.7602 6.6021 .0109
Within Groups 195 1.1754

Total 196

 

The spoilage indicators were more important to female shoppers(mean =4.6822) than the male
shoppers.(mean =4.2647) The results are shown in Table 31.

Table 31. Results of the Descriptive Analysis of Shoppers by Gender on Q0604: “Shopper’s Preference on
Smilage Indicators for Perishable Foods”

 

 

 

 

 

Gender Mean Std Dev Cases
Male 4.2647 1.3672 68
Female 4.6822 .9013 129
Total 4.5381 1.0995 197
Total Cases = 200

MissingCases=3or 1.5Pct

There was a significant diflerence by the type of shoppers on q0604, with significance of .0115.
See Table 32.

Table 32. ANOVA of Shoppers by Type of Shoppers on Q0604: “Shopper’s Preference on Spoilage
Indicators for Peris_»h_able Foods.”

 

 

 

Som'ce d.f. Mean Square F-Ratio Sig.
Between groups 1 7.2764 6.5020 .0115
Within Groups 194 1.1191

Total 195

 

The spoilage indicators were more important to shoppers (mean =4.6331) than the non-
shoppers.(mean =4.0741) The results are shown in Table 33.

 

 

 

69

Table 33. Results of the Descriptive Analysis of Shoppers by Type of Shoppers on Q0604: “Shopper’s
Preference on Spoilage Indicators for Perishable Foods.”

 

 

 

Shopper Mean Std Dev Cases

Non-shopper 4.0741 1.4122 27

Shopper 4.6331 .9918 169
Total 4.5561 1.0727 196

 

 

Total Cases = 200
Missing Cases = 4 or 2.0 Pct

As shown in Table 34, there was a significant diflerence of shoppers by age, with a F -value of
.0031.

Table 34. AN OVA of Shoppers by Age on Q0604: “Shopper’s Preference on Spgilage Indicators for
Perishable Foods.”

 

 

 

Source d.f. Mean Square F-Ratio Sig.
Between groups 2 6.8573 5.9589 .0031
Within Groups 194 1.1508

Total 196

 

Yormger groups (54 or younger years) tended to prefer spoilage indicators for perishable foods.
The Scheife test showed mat the age of 55-or-older-years group(mean = 4.1356) was significantly different
from the other age groups. Results are shown in Table 35.

Table 35. Results of the Descriptive Analysis of Shoppers by Age on Q0604: “Shopper’s Preference on
- Spoilgge lndica_tors for Perishable Foods.”

 

 

 

 

 

 

 

Age Mean Std Dev Cases
Under 34 4.6800 .7677 50

35 - 54 4.7273 .8405 88

55 or older 4.1356 1.5138 59
Entire Population 4.5381 1.0995 197
Total Cases = 200

MissingCases=3or 1.5Pct

As shown in Table 36, there was a significant difiermce of shoppers by distance on q0902; the
significance was .0231.

Table 36. ANOVA of Shoppers by Distance on Q0902: “Shopper’s Preference on Sell-by Dates for Semi-
pe_g'shable Foods.”

 

 

 

Source d.f. Mean Square F-Ratio Sig.
Between groups 2 4.7765 3.8415 .0231
Within Groups 193 1.2434

Total 195

 

Schefie test showed that there was a significant difl‘erence between shorter—than-S-minutes distance
group(mean = 4.1628) and 6-to-10-minutes group(mean = 3.7101). Results are shown in Table 37.

 

 

 

70

Table 37 . Results of the Descriptive Analysis of Shoppers by Distance on Q0902: “Shopper’s Preference
on Sell- Dates for Semi- erishable Foods”

 

 

 

Distance Mean Std Dev Cases

Shorter than 5 minutes 4.1628 1.0500 86
6 to 10 minutes 3.7101 1.0995 69
Longer than 10 minutes 3.7317 1.2654 41
Entire Population 3.9133 1.1312 196

 

Total Cases = 200
Missing Cases = 4 or 2.0 Pct

As shown in Table 38, q0903 had a significant difference by level of education; the probability of
the F-value was .0139.

Table 38. ANOVA of Shoppers by Education on Q0903: “Shopper’s Preference on Use-by Date for Semi-
perishable Foods.”

 

 

 

Source (if. Mean Square F-Ratio Sig.
Between groups 4 3.3870 3.2178 .0139
Within Groups 192 1.0526

Total

 

As increased the level of education, there was a tendency to increase preference on use-by dates
for semi-perishable foods. The shoppers holding graduate or professional studies degree had a mean of
4.4727, whereas some-high-school-or-less group had a mean of 3.1250. In addition, the Schefi‘e test
showed that the significant difierence between some-high-school-or-less group and some college group or
' graduate or professional studies group. See Table 39.

Table 39. Results of the Descriptive Analysis of Shoppers by Education on Q0903: “Shopper’s Preference
on Use-by Dates for Semi-perishable Foods”

 

 

 

 

 

Education Mean Std Dev Cases
Some high school or less 3.1250 1.6421 8
Completed high school 4.1875 1.2032 32
Some college 4.3654 .9907 52
Bachelor’s degree 4.2200 .9957 50
Graduate or professional studies 4.4727 .8575 55

Entire Population 4.2792 1.0489 197

Total Cases = 200

Missing Cases = 3 or 1.5 Pct

There was a significant difference (the significance of .0423) by number of adults on q1001;
“Shopper’s perception on semi-perishable foods after use-by date was passed.” The results are shown in
Table 40.

Table 40. ANOVA of Number of Adults on Q1001 : “Shopper’s Preference on Semi-periglgble Foods after
Use-by Date.”

 

 

 

Source d.f. Mean Square F-Ratio Sig.
Between groups 2 .7692 3.2138 .0423
Within Groups 195 .2393

Total

 

 

 

 

 

 

71

There was a significant difierence of shoppers by the number of adults in household on q1001.
With only one adult in the household, the mean was 1.5333, whereas with more than two adults, the mean
was 1.7813. See Table 41.

Table 41. Results of Descriptive Analysis by Number of Adults on Q1001 : “Shopper’s Perception on Semi-
perishable Foods after Use-by Date.”

 

 

 

No. of Adults Mean Std Dev Cases
One 1.5333 .5045 45
Two 1.5455 .5000 121
More than two 1.7813 .4200 32
Entire population 1.5808 .4892 198

 

 

Total Cases = 200
Missing Cases = 2 or 1.0 Pct

As shown in Table 42, there was a significant difl'erence by the number of adults on ql 301;
“shoppers perception on shelf-stable foods afier use-by date. The significance was .0207.

Table 42. ANOVA of Shoppers by Number of Adults on Q1301: “Shopper’s Perception on Shelf-stable
Foods after Use-by Date.”

 

 

 

Source d.f. Mean Square F-Ratio Sij.
Between groups 2 .8987 3.9568 .0207
Within Groups 195 .2271

Total 197

 

As increased in the numbers of adults in their household, they agreed to use shelf-stable foods after
use-by date. With only one adult in household, the mean was 1.5556, whereas with more than two adults,
the mean was 1.8438. See Table 43.

Table 43. Results of the Descriptive Analysis by Number of Adults on Q1301: “Shopper’s Perception on
Shelf-stable Foods after Use-by Date.”

 

 

 

 

 

No. of Adults Mean Std Dev Cases
One 1.5556 .5025 45
Two 1.6033 .4912 121
More than two 1.8438 .3689 32
Total 1.6313 .4766 198
Total Cases = 200

Missing Cases = 2 or 1.0 Pct.

As shown in Table 44, there was a significant difference of shoppers by level of children on
ql301; “Shopper’s perception on shelf-stable foods after use-by date.” The F-value was .0069.

Table 44. ANOVA of Shoppers by Level of Children on Q1301: “Shopper’s Perception on Shelf-stable
Foods alter Use-by Date.”

 

 

 

Source d.f. Mean Square F-Ratio Sig.
Between groups 1 1.6947 7.4525 .0069
Within Groups 194 .2274

Total 195

 

 

 

 

 

72
Table 45 shows that more shoppers, with no children (mean = 1.6992), tended to agree to use shelf
stable foods after use-by date than shoppers with children (1.5068).

Table 45. Results of Descriptive Analysis by Number of Adults on Q1301: “Shopper’s Perception on
gulf-stable Foods after Use-by Date.”

 

 

 

 

Children Mean Std Dev Cases
No children 1.6992 .4605 123

l or more children 1.5068 .5034 73
Entire population 1.6276 .4769 196
Total Cases = 200

Missing Cases = 4 or 2.0 Pct.

As shown in Table 46, ql 301 had a significant difference by Shopper’s shopping frequency; the F-
value was .0164.

Table 46. ANOVA of Shoppers by Shopping Frequency on Q1301: “Shopper’s Perception on Self-stable
Foods after Use-by Date.”

 

 

 

Source d.f. Mean Square F -Ratio Sig.
Between groups 2 .7903 3.5073 .0164
Within Groups 194 .2253

Total

 

Everyday shoppers (mean = 1.3333) had less tendency to use shelf stable foods alter use-by date
than other groups. In addition, the Schefi‘e test showed that there was a significant difierence between
everyday shoppers and more-than-once-a-week shoppers or less-than-once-a-week shoppers. See Table 47 .

Table 47 . Results of Descriptive Analysis by Shopping Frequency on Q1301: “Shopper’s Perception on
Self-stable Foods after Use-by Date.”

 

 

 

 

 

Shgpirg frequency Mean Std Dev Cases
Everyday 1.3333 .4851 l 8
More than once a week 1.7059 .4602 51
Once a week 1.6044 .4917 91
Less than once a week 1.7368 .4463 38
Entire population 1.6313 .4747 198
Total Cases = 200

 

Missing Cases = 2 or 1.0 Pct

 

 

APPENDIX D

LENGTH OF INTERVIEW TIME

 

73

APPENDIX D

Length of Interview Time

The interview was designed to be 10 minutes long. 44 percent of interviews were
taken within 10 minutes or less. In many cases, the participants were eager to ask

questions and discuss the subject in more depth, and so many interviews were required

more time. See Table 48.

Table 48. Distribution of Participants by Length of Interview Time.

 

 

Time (minute) Number Percent of Population
less than 10 minutes 30 15.0
10 minutes 58 29.0
lO<< 15min. 52 26.0
15<<20 min. 51 25.5
20 minutes or over 4 2.0
Missing 5 2.5

 

Total 200 100.0

 

 

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74

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