Construction and Validation
Of a Nutrition Test
Marielle Prefontaine
A standardized test to measure nutrition knowledge of a variety of adult groups has
been· developed in Canada.
Summary
A 25-item nutrition test was developed. based on concepts presented
by the Interagency Committee on Nutrition Education (ICNE). The
goal of the test was a valid. reliable instrument to assess levels of
nutrition knowledge of four groups of adults.
Objectivity. reliability. and validity are among importa,nt factors in
judging quality of a test. In this study. objectivity of the items was
ascertained by a group of senior and graduate students in nutrition.
The internal consistency measure of reliability was obtained for each
group participating in the study. Conte.nt validity was established in
two ways: behavioral objectives were based on the leNE concepts and.
second. expert judges assessed the relative importance of these objectives. Construct or concurrent validity. the ability of the test to
measure performance on a nutrition test. was assessed by testing groups
expected to score high or low (based on training they received in nutrition or related fields). Home economics teachers. because of previous
training. obtained the highest scores mean score on the test; health
science students reached the ideal mean; and mothers and immigrants
considered to be lay groups had the lower mean scores.
To construct the test the following steps were taken. First,
important educational goals for the general adult population
were developed based on the ICNE concepts (see Table 1).
It was not felt necessary nor desirable to define all goals that
could be generated from these concepts; only those recognized
as important by authoritative judgments were sought. Table 1
lists the four ICNE concepts and the goals considered as important for the general adult population to make right decisions about food to maintain optimum health.
Second, the defined goals were transcribed into operationally defined abilities or behavioral objectives. A series of such
objectives was submitted to six dietitians for comments and
addition of other relevant objectives. A total of 184 objectives
Table I
ICNE Concepts and Related Nutrition Goals
ICNE concepts
Evaluation is an integral part of any educational process.
To function effectively, nutrition educators need to gather information on how much a given population knows about
nutrition. Evaluation methods can vary all the way from personal judgments to standardized tests. The purpose of this
study was to construct a test instrument to evaluate nutrition
knowledge which can be applicable to different groups of
adults.
There have been previous attempts to evaluate nutrition
knowledge. In 1956, Young et al. (1) designed a I-hour interview for homemakers which covered topics such as the foods
to be eaten daily, the meaning of a balanced diet, the importance of the basic food groups and the nutritive value of substitute foods. Morse et al. (2) administered Kilander's nutrition test to homemakers; no information was given on which
topics or aspects of nutrition the test was trying to measure.
Eppright and Fox (3) gathered information on the nutrition
knowledge of mothers through 35 true-false statements on
meal planning, food preparation, and food behavior of their
child. McCarthy and Sabry (4) gathered information on nutrition misconceptions of university students through 70 truefalse statements. Dwyer et al. (5) designed a questionnaire
for high school students based on nutrition concepts presented
in textbooks. From the review of literature, it appears that
the approaches used to assess the level of nutrition knowledge
were either covering only a limited area of nutrition or were
geared to high school students.
Construction of Test
This study intended to develop a test based on basic nutrition concepts and applicable to a variety of adult groups. To
achieve this, the four concepts presented by a subcommittee
of the Interagency Committee on Nutrition Education (ICNE)
were considered appropriate. These concepts, as Leverton (6)
said, summarize all the nutrition knowledge that is applicable
to food-for-people-for-health.
THE AUTHOR is Associate Professor, Ecole des Sciences Domestiques, Universite de Moncton, Moncton, N.B., Canada.
152
I
Journal of NUTRITION EDUCATION
Nutrition is the
food you eat a,nd
how the body uses
it.
II
Food is made up of
different nutrients
needed for growth
and health.
Goals formulated by a team of professionals·
- To understand the importance and the role
of foods
- To understand the nutrition needs of the
body
- To understand the functions of the major
nutrie.nts and their food sources.
-
To understand the importance of a sound
and well-balanced diet and to know about
different sources of information
- To know the recommendations contained
in the Canadia,n Food Guide
- To understand certain health problems associated with poor eating habits.
III
All persons.
throughout life.
have need for the
same nutrients but
in varying amounts.
IV
The way food is
handled influences
the amount of
nutrients in food.
its safety. appeara,nce and taste.
- To understand the nutritional
of children
- To understand the nutritional
of adolescents
- To understand the nutritional
of adults
- To understand the nutritional
of pregnancy and lactation
- To understand the nutritional
of the elderly.
requirements
requirements
requirements
requirements
requirements
- To understand the effect of stor.age on nutritive value. appearance and flavor of food
- To know how to freeze fresh and cooked
foods
- To understand the effects of various cooking methods
- To know that the food industry is under
government control.
*A team of. experts comprising two university professors of nutrition. two profeSSionals In adult education and four graduate students in nutrition arrived
at a consensus on what constituted important goals, for the adults, to adequately cover the nutrition field.
Vol. 7, No.4. October-December. 1975
were retained as . pertinent abilities required in nutrition for
the general adult population.
Third, considering that it would be appropriate to produce
a short nutrition test, it was decided to reduce the number
of behavioral objectives from which the test items would be
prepared. Thus a random sample of 100 behavioral objctives
was drawn from the 184.
Fourth, 100 items based on these selected, objectives were
written. The format was that of four multiple-choice items
following the procedures described by Ebell (7) and Thornike
(8).
Fifth, the objectivity of the items was ascertained by a
group of senior and graduate students in nutrition. An item
was considered objective when there was a consensus that it
had only one correct answer of the four alternatives.
Sixth, the readability of the items and the timing were
checked with different groups of adults: 12 homemakers, 12
secretaries, 12 librarians, 14 adults attending night classes,
and 23 freshmen students. When it appeared possible and
promising, items were reformulated to increase clarity and
modify the proportion of respondents that would agree with
the four alternatives of the multiple-choi::e items. Of the 100
items, 26 had to be discarded because it was too difficult to
find distractors that would be definitely incorrect but plausibly
attractive to the uninformed.
Seventh, the remaining items were tested on two groups:
one was 111 women adults in waiting rooms of beauty parlors
and the other was 93 adults attending night classes. An itemanalysis was done using the Testat Program (9). This program
computes (a) the item difficulty index (percent of respondents
answering each item correctly), (b) distribution of answers to
alternatives (percent of respondents marking each alternative),
and (c) the discrimination coefficients (correlations of item
scores with total scores on the test in which the item is .included). Thirty items were retained for the nutrition test. The
internal consistency measure of reliability, determined by an
analysis of variance method, the Richardson's formula (10),
was found to be 0.81. This coefficient indicates that the test
items represent a relatively homogenous universe of nutrition.
668 students tested represented approximately 72 % of the
total population (927).
Mothers. This group was sampled randomly from obstetrics
departments of the 15 French hospitals in Montreal Island.
Twenty percent of the total occupancy on the day of the visit,
during October and November 1972, was selected. A research
assistant administered 127 nutrition tests.
Immigrants. This group was selected from the four Centres
d'Orientation et de Formation des Immigrants (COFI) in Metropolitan Montreal. All immigrants who passed their French
exam between October 1972 and January 1973 answered a
questionnaire under the supervision of a research assistant.
Of the 249 questionnaires, 41 had to be discarded since they
were incomplete.
Table 2 presents the characteristics-sex, years of schooling, age, and previous nutrition training-of these four groups
of adults. All home economics teachers reported previous
training in nutrition. Some health science students (19%)
had taken a course in nutrition besides their training in related fields of nutrition, biology, and physiology. More than
one third, 34%, of the mothers had had learning experiences
in nutrition at different levels.
Results
Of the 30 items, 25 had the required discrimination indices
(above the 0.30 level). The coefficient of reliability of this
25-item test was 0.68 for the home economics teachers, 0.64
for the health science students, 0.67 for the mothers, and 0.69
for the immigrants.
From the 25-item test, an individual's score was obtained
by giving a weight of one to each correct answer. The home
economics teachers obtained the highest mean score of 19.6;
the health science students had a mean score of 15.7, a figure
which approached the ideal mean 1 of the test which was 15.9.
The mothers and the immigrants obtained mean scores of
12.5 and 10.2, respectively.
Table 2
Description of the Four Groups of Adults
Participating in the Tryout Programs
The Tryout Programs
Populations. The 30 item-questionnaire was administered
to four groups of adults. These groups were selected because
of their various levels of exposure to nutrition or related fields.
One group was home economics teachers who had received
previous exposure to formal courses in nutrition. The second
was students enrolled in their first year of university health
science training; they had had some previous training in nutrition. The third group was lay persons with respect to nutrition: a cross-section of mothers having just given birth to a
child in hospital. The fourth group was comprised of immigrants; it was felt they would have the least abilities in an
unavoidable culture-bound nutrition test.
Home Economics Teachers. This group was sampled from
French home economics teachers in the province of Quebec.
A research assistant mailed a questionnaire during September
1972 to a random sample of 50%; three followups were sent
to tardy respondents and by December 1972, 169 completed
questionnaires were received, a 64% return.
Health Science Freshmen Students. Approval for testing
the students was obtained from the directors of the Health
Science Section at the Universite de Montreal. The test was
given in January 1973 with questionnaires completed during
class time under the supervision of a research assistant. The
lA point midway between the maximum possible score and the expected chance scores is regarded as the ideal mean. The expected
chance score equals the number of items in the test divided by the
number of choic9s per item. Since with 25 four-choice items, the expected score is 6.25, the ideal mean in this case is 15.9.
Vol. 7, No.4, October-December, 1975
Population
Characteristics
Sex
Male
Female
Years of schooling
<10 years
10-12 years
> 12 years
Age
<25 years
25-30 years
>30 years
Previous nutrition
training
With training
Without training
Home
economics
teachers
n=169
Health
science
students
n=668
Mothers
n=127
Immigrants·
n=208
'10
%
%
%
100
48
52
100
55
45
100
100
36
41
23
17
29
54
7
17
76
t
t
t
40
40
20
32
3S
33
100
19
81
34
66
100
'They came from Latin America (34%), Africa or Asia (28%), Oriental Europe
(17%), England, Germany, Australia (16%), and other countries (5%). Sixtysix percent of them were In Canada 4 to 12 months; the others more than
one year.
tThe specific age of the health science freshman students was not requested
but the average of such a group Is approximately 20 years of age.
Journal of NUTRITION EDUCATION
I
153
The home economics teachers who obtained the highest
mean score had had previous courses in nutrition. The mean
score of the health science students appears to reflect their
training in fields related to nutrition. Within this group, those
(19%) who reported previous courses in nutrition obtained
higher scores than those without previous courses, p. < .001.
With the mothers, the test scores followed the same trend:
those who reported previous nutrition courses (34%) obtained
higher scores than those without previous courses, p. < .10.
When the number of years of schooling was held constant,
the influence of previous nutrition courses had a marked effect
on the test scores. Of the mothers who reported more than 12
years of schooling, 75% of those who had previous nutrition
courses obtained a score above the ideal mean. Although the
level of education always appears to be associated with the
level of knowledge in nutrition (1-3), it is evident from this
study that previous learning experiences in nutrition have a
marked effect.
It is hoped that nutrition educators in search of an instrument to measure knowledge in nutrition of adult groups will
benefit from the expertise, time, and persistence invested in
the development of the present nutrition test2 and that they
will feel welcome to use it.
Project supported by National Health Grant No. 607-7-787 made
by the Department of National Health and Welfare (Canada).
SA copy of the test in either French or English may be obtained from
the author.
Spectrum
(Continued from page 148)
naire before and after exposure to an
educational program designed to inform
them about nutritional labeling.
Nutritional information, along with
open dating, unit pricing and names of
specific ingredients, was listed as information desired by consumers prior to the
educational program. Following the program, total mention of nutritional information increased, but percentage of
respondents wanting nutritional information did not greatly exceed the percentage
wanting other types of information such
as open dating.
The article points out that studies in
the U.S. indicated a higher degree of consumer preference for nutritional labeling.
Often the surveys were concerned only
with nutritional labeling, giving the respondents-in effect-a choice of being
"for" or "against," rather than stating
preferences about different types of labeling information.
While this study did not attempt to
measure the extent to which consumers
would actually dse nutritional labeling,
nutrition educators should note that even
after a brief educational program on nutritional labeling many of these consumers ranked other label information as
having higher priority.
Consumer Use of Nutrition Information
on Food Labels, Babcock, M.J., Burkart,
A., Guthrie, H., Lichtenstein, A. and
Thoroughgood, C., New Jersey Agricultural Experiment Station Bulletin 844,
154
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Journal of NUTRITION EDUCATION
ACKNOWLEDGEMENTS
This study was done in 1971-73 at the Institut de Dietetique et de
Nutrition, Universire de Montreal. Professors and graduate students as well as professional dietitians and adult educators became
involved in this operational research. To all of them, the author
expresses her gratitude for their prompt response to her requests
for assistance.
REFERENCES
1. Young, c., Berresford, K. and Waldner, B.G., What the homemaker knows about nutrition, II: Level of nutrition knowledge,
J. Am. Dietet. Assn., 32:29, 1956.
2. Morse, E.F., Clayton, M.M. and Cosgrove, L., Mothers' nutrition knowledge, J. Home Econ., 59:667, 1967.
3. Eppright, E.S. and Fox, H.M., The North Central regional
study of diets of pre-school children, J. Home Econ., 62:327,
1970.
4. MoCarthy, E. and Sabry, J.H., Canadian university students'
nutrition misconceptions, J. Nutr. Educ., 5: 193, 1973.
5. Dwyer, J.T., Feldman, J.J. and Mayer, J., Nutritional literacy
of high school students, J. Nutr. Educ., 2:59, 1970.
6. 'Leverton, R.M., Development of basic nutrition concepts for
use in nutrition education, in Proceedings of Nutrition Education Conference, Feb. 20-22, 1967, U. S. Dept. of Agriculture
Misc. Pub!. No. 1075, Washington, D.C., 1968.
7. Ebell, R.T., Measuring Educational Achievement, PrenticeHall, Inc., Englewood Cliffs, N.J., 1955, pp. 144-181.
8. Thorndike, R.L., Educational Measurement, 2nd ed., American
Council on Education, Washington, D.C., 1971.
9. Velman, D.J., Fortran Programming for the Behavioral Sciences, Holt, Rinehart & Winston, Inc., New York, 1967, pp.
178-181.
10. Kuder, G.F. and Richardson, M.W., The theory of estimation
of test reliability, Psychometrika, 2:151,1937.
Sept. 1975. From Bulletin Clerk, Publications Distribution Center, Cook College, Rutgers University, P.O. Box 231,
New Brunswick, NJ 08903,51 pp., single
copy free.
The chronological development of
FDA's nutritional labeling program is
outlined in this bulletin along with the
purposes of nutritional labeling. Suggestions for minor modification of the present labeling format to improve its usefulness to consumers are also given. A
statement in the FDA regulation governing labeling indicates that "The Commissioner will review the regulation periodically . . . and will propose and adopt
whatever changes are shown to be in the
public interest."
The main change recommended by the
authors is to list all data for one standardized reference portion size defined by
food energy content (with household
measures and weights also given) so foods
can be compared on an equal calorie
basis. Thus, on-the-spot comparison
shopping for nutritious foods would be
made easier.
The authors also recommend the adoption of average RDAs for a typical family. They argue that by including average
energy allowance it would be easier to
develop popular nutrition education materials utilizing nutrient-calorie relationships (nutrient density) for meal planning
purposes.
Another recommendation is to list typical or year-round average values for
certain products which can vary in l'lutritive value (such as vegetables) to make
the data consistent with USDA food
composition tables.
The authors feel strongly about increasing the usefulness of nutrition labeling to the average consumer and feel
these recommendations if implemented
would contribute to that end.
Lactose Intolerance
Milk intolerance and malnutrition, Bradfield, R.B., Jelliffe, D.B. and Ifekwunigwe, A., Lancet, 2:325, Aug. 16, 1975.
In a letter to the editor, the subject of
milk intolerance (due to lactose content)
in the malnourished child living in the
tropics is discussed.
The authors point out that "while milk
intolerance in the well-nourished child
living in temperate areas is, at best, disagreeable, it may be catastrophic for the
malnourished child living in the tropics."
Dry skim milk powder is often the lowest-cost and readily available food available for famine relief. The authors suggest the addition of other nutrients, such
as fat and sucrose, would have the beneficial effect of reducing the relative lactose concentration while providing a
higher-energy food mix for "catch up"
growth.
Enzyme treatment of milk, Agricultural
Research, USDA, 24(No.2):6, August
1975.
Lactose-intolerant individuals may one
day be able to drink a special enzymetreated milk without suffering the usual
symptoms of lactose intolerance. Milk
treated with lactase enzyme (derived
from yeast) is more easily tolerated by
(Continued on page 172)
Vol. 7, No.4, October·December, 1975