A Nutrition Knowledge Test for Nutrition Educators
Carol Byrd-Bredbenner
College oj Human Development, The Pennsylvania State University
University Park, Pennsylvania 16802
This paper describes the development of a criterion-referenced instrument for assessing nutrition knowledge of potential nutrition educators. The test consists of 50 multiple-choice items. It addresses 3 content areas- basic nutrition principles, sources of nutrients, and function of nutrients; and it measures 4 cognitive levels
-recall, comprehension, application, and analysis. The results of an administration
of the test to 576 college graduates demonstrate that the instrument discriminates between groups of professionals who are trained in nutrition and those who are not.
(JNE 13:97-99, 1981)
ABSTRACT
With the current interest in nutrition
education programs, many individuals with
a variety of backgrounds have undertaken
or have been assigned the task of teaching
nutrition (1-3). Since many view these individuals as experts, they may influence
others to a great extent, even though they
may have little or no formal nutrition training (4-6). An evaluation instrument which
measures nutrition knowledge of potential
nutrition educators could serve to select
qualified nutrition educators, to identify
those who need more training in nutrition,
and to maintain quality nutrition education
programs. This paper describes the development and validation of such an instrument.
TEST DEVELOPMENT
The plan for development of this instrument followed the rules of test construction
offered by Gronlund (7) and by Ahmann
and Glock (8). Similar to those described by
Eppright et al. (9), 3 broad nutrition concepts-basic nutrition principles, sources of
nutrients, and functions of nutrientsserved as the framework for the test. A panel of 6 nutrition experts reviewed and approved these concepts as important to understanding the application of nutrition.
This panel also reviewed objectives that had
been written for each concept. They selected 13 objectives judged to reflect basic,
rather than advanced, nutrition knowledge.
This panel of nutrition experts also addressed the issue of the relative importance
of the concepts and objectives. They decided that the concept of basic nutrition
principles was most important and would
be addressed by half of the items in the test.
They perceived the concepts of nutrient
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sources and of nutrient functions to be less
important but of approximately equal importance relative to each other. The nutrition experts also reviewed and revised for
accuracy 94 multiple-choice items that had
been constructed to measure knowledge of
the concepts and objectives. A panel of 7
experts in educational measurement evaluated the construction of items and categorized the revised items according to the first
4 cognitive levels-recall, comprehension,
application, and analysis-of Bloom's taxonomy (10). The test items corresponded to
a ninth-grade reading level according to the
readability scale constructed by Fry (11).
Thus, reading difficulty would not compromise the performance by the intended, college-educated users of the test. A group of
20 graduate students and staff in nutrition
and home economics education completed
a pilot test of the 94 items. Items answered
incorrectly by more than 30010 of this group
were eliminated on the basis that the question was poorly constructed, misleading, or
more advanced than could be considered
basic nutrition.
To make up the final 50-item test instrument, test items that met the difficulty index
criterion of 0.7 or greater and were in the
comprehension, application, or analysis
category were selected preferentially to ensure that this instrument would measure nutrition knowledge at levels higher than the
recall level. The high difficulty index, i.e.,
one that required items to be quite easy, reflected the design of this test as a criterionreferenced or mastery test. The participants
of the pilot test, nutrition and home economics graduate students and staff, should
have mastered the basic nutrition knowl-
edge that every individual responsible for
nutrition education should possess. Recall
items meeting the difficulty index criterion
were added after inclusion of all higher level
items. Appropriate representation of the
nutrition concepts also received consideration in the item selection process.
A group of 35 college students from a variety of majors completed a pilot test of the
final 50-item instrument. This testing provided data for further item analysis, for determination of internal consistency, and for
revision. The mean score for the college students was 38.5, with the range from 20 to
50. The reliability was 0.86, as calculated by
the Kuder-Richardson 20 (K-R 20) formula
(7,8). The major refinement resulting from
this pilot test was identification and revision
of nonfunctioning distractors.
Table 1 displays the final distribution of
test items according to nutrition concepts
and cognitive levels. The table of specifications that guided item construction and selection throughout the process required that
4 cognitive levels be represented and that
basic nutrition principles receive more emphasis than sources of nutrients or functions of nutrients. Content validity of the
final test instrument is ensured because the
table of specifications reflects expert opinion in nutrition and in measurement.
VALIDATION DESIGN
The purpose of this validation study was to
determine whether the test instrument
would distinguish groups of professionals
with nutrition training from groups without
nutrition training and to examine reliability
of the instrument. The 77,556 graduates
from Pennsylvania State University between 1968 and 1978 served as the population from which the test validation sample
was drawn. This population included 346
nutritionists, 448 home economists, 1,240
nurses, 1,207 health and physical educators,
and 773 elementary educators. Examination of college records established that
graduates of nutrition majors were required
to take several nutrition courses and that
some formal nutrition coursework also was
JOURNAL OF NUTRITION EDUCATION
97
required for graduation in home economics, nursing,and health and physical education. No formal requirement for coursework in nutrition existed for graduation in
elementary education or for a bachelor's
degree in general.
A random selection of 300 individuals
from each group plus 300 additional persons from the remaining 73,542 graduates
of other majors comprised the sample.
These subjects received a survey form containing a request for demographic information, the 50-item test instrument, and instructions for completion and return of the
survey. Participation was voluntary and
anonymous. One to 10 years had elapsed
since these graduates had received their baccalaureate degrees. This length of time allowed for variations in age, postbaccalaureate study, pursuit of professional activities,
and other such demographic characteristics
so that this sample could be considered generally representative of professionals in
their respective fields of study.
RESULTS
Overall, of the 1,800 subjects surveyed, 576
(32070) returned completed test instruments.
The response rate varied among groups; respondents included 45% of the nutritionists, 31 % of the home economists, 35% of
the nurses, 26% of the health and physical
educators, 26% of the elementary educators, and 29% of the graduates in other majors. The possibility exists that respondents
could represent a biased sample of each
group. Return of the survey was voluntary,
and rtc> comparable nutrition knowledge
data are available for nonrespondents.
However, analysis of the age, race, and sex
distribution of respondents revealed no significant differences from the distribution of
these characteristics of the entire population. Therefore, the nutrition knowledge of
the respondents is likely to reflect the level
of nutrition knowledge of each professional
group. The assumption that elementary
educators and college graduates in general
would be groups with little nutrition training proved to be correct; 83% and 82%,
respectively, of elementary educators and
college graduates in general reported no
formal coursework in nutrition.
The 576 tests underwent item analysis to
determine the degree of difficulty of individual items for the 6 groups of respondentsnutritionists, home economists, nurses,
health and physical educators, elementary
educators, and other college graduates.
Overall, 28 of the 50 test items had a rela-
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JOURNAL OF NUTRITION EDUCATION
Table 1
Distribution of items in the final test according to nutrition concepts and cognitive levels
Concepts
Cognitive Levels"
Recall
Comprehension
3
6
3
12
12
6
8
26
Basic nutrition principlesb
Sources of nutrientsC
Functions of nutrientsd
Totals
Application
Totals
Analysis
7
2
3
0
25
14
0
9
0
3
11
50
aDescribed by Bloom et al. (Ref. 10)
bItems addressed the topics of 4 food groups (3 items), nutrient density (3 items), energy (4 items), weight control (3
items), food preparation (2 items), and nutrient needs (10 items).
cItems addressed the topics of bread and cereal (3 items), dairy products (3 items), protein foods (4 items), fruits and
vegetables (3 items), and energy (1 item).
dltems addressed the topics of general functions (6 items) and specific functions (5 items).
Table 2
Internal consistency (Kuder-Richardson 20) of the total test and subtests by group
Subtests
Group (n)
Nutritionists (134)
Home economists (93)
Nurses (l05)
Health and physical educators (77)
College graduates, general (88)
Elementary educators (79)
Total respondents (576)
Total Test
Basic Nutrition
Principles
(25 Items)
Sources oj
Nutrients
(14/tems)
Functions oj
Nutrients
(11 Items)
0.468
0.602
0.603
0.598
0.629
0.600
0.694
0.435
0.349
0.256
0.319
0.231
0.286
0.542
0.391
0.480
0.397
tively high difficulty index (0.80 to 1.(0),
indicating that 80% or more of all respondents correctly answered these 28 items.
Among nutritionists 41 items had a high
difficulty index; in contrast, only 20 of the
50 test items received correct responses
from over 80% of elementary educators.
Thus, consistent with the objective of a
criterion-referenced or mastery test, more
test items were easier for persons trained in
the subject, e.g., nutritionists, than for per
sons without such training, e.g., elementary
educators.
Table 2 presents the K-R 20 internal consistency coefficients for the total test and for
the 3 subtests associated with the 3 nutrition
concepts addressed by the test. The K-R 20
provides a conservative estimate of reliability for an untimed, single administration of
a single form of a test (8). The overall K-R
20 for the total test for the entire sample of
576 was 0.816. Reliabilities for various professional groups were between 0.639 and
0.738. High reliability coefficients are associated with tests that contain a wide range
of item difficulty and high item discrimination indices. Since this test contained a pre-
(50 Items}
0.639
0.729
0.677
0.722
0.738
0.675
0.816
0.510
0.520
0.424
0.577
ponderance of easy items, one would not
expect exceptionally high reliability coefficients. The subtest reliability coefficients
for specific groups of respondents were
quite low in many cases, especially the subtests with a small number of items. However, the overall reliabilities of the subtests
calculated from the entire sample of 576 respondents were reasonable, considering the
high difficulty indices. These subtests could
be used to identify specific areas of poor nutrition preparation among potential nutrition educators.
Table 3 presents the mean score on the
nutrition knowledge test for each group of
professionals. One-way analysis of variance
followed by Tukey's method (12) served to
assess the significance of differences between means. Nutritionists achieved significantly higher mean scores on the nutrition
knowledge test than all other groups; home
economists scored significantly higher than
did all other groups except nutritionists;
and nurses, health and physical educators,
and college graduates in general all scored
significantly higher on the nutrition knowledge tests than did elementary educators. In
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Table 3
Nutrition knowledge scores of groups
Scoret
Group (n)
Mean±SD
Nutritionists (134)
Home economists (93)
Nurses (105)
Health and physical educators (77)
College graduates, general (88)
Elementary educators (79)
Total (576)
44.1 ± 3.4a
4O.9±4.6b
37.1 ±4.6c
35.7 ± 5.2c
35.6± 5.4c
33.0± 5.0<1
38.4±6.0
tScores followed by different letters are significantly different (p > 0.05), as determined by ANOVA.
general, group comparisons of subtest
scores followed the same pattern: nutritionists scored highest, home economists and
nurses scored better than the remaining
groups, and elementary educators had the
lowest mean scores on subtests.
These results demonstrate the concurrent
validity of the test and that the test functions as a criterion-referenced or mastery
test. The professionals with the most nutrition training as undergraduates presented a
higher level of mastery than did those with
fewer or no such formal courses in nutrition. This test may therefore serve as a tool
for determining the mastery or understanding of nutrition subject matter of those persons responsible for or expected to teach
nutrition.
D
NOTE
These data were taken in part from the doctoral
thesis of Carol Byrd-Bredbenner entitled "The
Interrelationships of Nutrition Knowledge, Attitudes Toward Nutrition, Dietary Behavior, and
Commitment to the Concern for Nutrition
Education," The Pennsylvania State University,
University Park, Pennsylvania, 1980. A single
copy of the test may be obtained from Carol
Byrd-Bredbenner, 202 Human Development
Building, The Pennsylvania State University,
University Park, Pennsylvania 16802.
LITERATURE CITED
1 Kohrs, M. B., J. Nordstrom, R. O'Neal, D.
Eklund, B. K. Paulsen, and A. Hertzler.
Nutritional status of main food preparers and
nutrition education assistants. Journal of the
American Dietetic Association 72:282-88,
1978.
2 Petersen, C., and C. Keis. Nutrition knowledge and attitudes of early elementary
teachers. Journal of Nutrition Education
4:11-15c, 1972.
3 Brittin, H. Nutrition education for elemen-
ENERGY
Energy expenditure changes with age,
body composition, gender, activity, and extremes of heat and cold, but presumably
not significantly within moderate changes in
comfortable environmental temperature.
M. J. D~uncey (British Journal of Nutrition 45:257-67, 1981) challenged this
presumption by measuring energy expenditure of 9 women confined, under carefully
controlled and standardized conditions, in
a calorimeter for 30 hours at 22°C (72°F)
H. E. Sours et al. (American Journal of
Clinical Nutrition 34:453-61, 1981) report
an investigation by the Center for Disease
Control and the Food and Drug Administration of 58 cases of sudden death among
obese persons undergoing rapid weight reduction with very low energy regimens. The
investigators excluded 14 cases because of
incomplete information and 27 cases because of coexistence of clinical disease,
mainly atherosclerosis or diabetes; in the remaining 17 cases, the sudden death apVOLUME
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1981
na/8:531-65,1971.
EXPENDITURE
and 28°C (82°F). The lower temperature
was cool but did not cause shivering, and
the higher temperature was warm but
caused sweating only infrequently for a
short duration. Despite the relatively small
difference in environmental temperature,
average energy expenditure was over 100
kcal greater per 24 hours in the cooler
chamber. Evaporative heat loss decreased
at the lower temperature, but sensible heat
loss increased to a greater extent for a net
FATAL
tary education majors. Journal of Nutrition
Education 3:73, 1971.
4 Godshall, G. A. Nutrition in the elementary
school. New York: Harper & Brothers Pubs.,
1958, pp. 39-82.
5 LaChance, P. Nutrition education. Journal
of Nutrition Education 3:52-53, 1971.
6 Schwartz, N. E. Nutrition knowledge, attitudes, and practices of Canadian public
health nurses. Journal of Nutrition Education 8:25-28, 1976.
7 Gronlund, N. E. Measurement and evaluation in teaching. New York: Macmillan Co.,
1968, pp. 79-131 and 249-278.
8 Ahmann, J. S., andM. D. Glock. Evaluating
pupil growth. 5th ed. Boston: Allyn & Bacon,
1975, pp. 149-257.
9 Eppright, E., H. M. Fox, B. A. Fryer, G. H.
Lamkin, and V. M. Vivian. The North Central regional study of diets of pre-school
children. 2. Nutrition knowledge and attitudes of mothers. Journal ofHome Economics 62:327-32, 1970.
10 Bloom, B. S., M. D. Englehart, E. J. Furst,
W. H. Hill, and D. R. Krathwohl. Taxonomy
of educational objectives: The classification '
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11 Fry, E. B. Readability graph: Clarifications,
validity, and extension to level 17 . Journal of
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12 Games, P. A. Multiple comparisons on
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RAPID
WEIGHT
positive increase in the cooler chamber.
Differences in metabolic rate disappeared
during mild exercise but remained fairly
constant at about 70/0 higher in the cooler
chamber during sleeping, sitting, standing,
and after meals. The author suggests that
small differences in environmental temperature, even in moderate climates, may influence energy balance to a greater extent than
S.M. O.
previously believed.
LOSS
peared related to the weight-loss regimen.
Prior to sudden death due to heart arrhythmias, these patients (16 women and 1 man;
aged from 23 to 51 years) lost 1.4 to 3.2 kg
per week for 2 to 8 months. Energy intake
during weight loss was 300 to 400 kcal per
day, mainly from "liquid protein" products,
supplemented with multivitamins and some
minerals and, in 11 cases, with potassium.
Ten patients neither smoked nor took nonnutrient medications; 12 were under some
degree of medical supervision. The most
frequent pathological finding was atrophy
of the heart. The authors recognized the inability to conclude a cause-and-effect
relationship between the low energy, protein-based weight-loss regimen and death
because of the uncontrolled nature of the
investigation. Nonetheless, they offer evidence that questions the safety of rapid
weight loss using liquid protein diets, even
when supplemented with vitamins and potassium and conducted under medical
supervision.
S.M 0
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