- Email: [email protected]
CAI in college-level nutrition education: a feasibility study
CAl in College-Level Nutrition Education: A Feasibility Study CAROL
P.
RIES AND JULIE GRANELL
Department of Foods and Nutrition, University of Illinois, Urbana, Illinois 61801 ABSTRACT' We developed a college-level computerassisted instruction (CAl) les son on vegetarianism and compared its effectiveness with the lecture/discussion method. Our independent CAl lesson consists of tutorial and drill-andpractice routines and a simple diet planning simulation. We collected pretest and posttest data on knowledge of and interest in vegetarianism from 44 students in an introductory foods and nutrition class. We randomly assigned three sections to receive either the CAl lesson, a comparable discussion lesson, or a lesson on another topic. There were no significant differences among these three groups either in pre- or posttest knowledge scores, or in interest in vegetarianism. CAl students' responses to learning by computer were positive. We discuss the potential savings in instructor and classroom time that may make CAl use advantageous as a substitute or (JNE 17:130-34, 1985) supplement to classroom teaching.
The increasing availability of computers and nutrition-related software has stimulated interest in the use of computer-assisted instruction (CAl) in nutrition education (1). Recent literature reports of computer applications in nutrition education include the use of CAl for college-Ievel introductory nutrition and diet therapy students (2-4) and for the general public in shopping malIs or fairs (5). as weIl as the use of computerized dietary analysis in various educational settings (6-9). However, most of these reports are descriptions of specific experiences and viewpoints of the educators involved. And while these reports stimulate further interest in CAl, research on its comparative effectiveness as an instructional method is needed to justify its widespread use in nutrition education (1). Research in many subject matter areas (10-12) has shown that CAl can be effective; however, thus far there has been little research on the effectiveness of CAl in nutrition education. This CAl evaluation project emerged from our concern over the lack of classroom time that was available to examine certain nutrition topics in our introductory college courses. Consequently, we hoped to de termine whether CAl was a feasible alternative to the lecture/discussion method for teaching foods and nutrition topics at the introductory college level. SpecificaIly, we sought to compare the effectiveness of our CAl vegetarianism lesson with the lecture/ discussion method. 130
JOURNAL OF NUTRITION EDUCATION
METHODS Computer les son development. FolIowing recommended design principles and procedures (13), we developed a lesson on the topic of vegetarianism for introductory-Ievel college students (Note 1). In a previous article (14), we have described the process that we used to design and develop the lesson and have presented our judgments concerning the feasibility of nutrition educators developing their own software. We chose vegetarianism as our topic for two reasons. First, although college students are frequently interested in this topic, in our curriculum, instruction in vegetarianism is often considered expendable due to constraints in class time. Second, sorne topics are more appropria te than others for interactive computer instruction. For example, if a topic is too complex or broad, a lesson with adequate interaction may require an unreasonable amount of user time (13). We felt that the relatively straightforward principles of vegetarianism could be presented in an interactive style within a reasonable amount of instruction time. Our vegetarianism lesson is designed for independent study on a microcomputer. Tutorial, and drill-andpractice routines present facts and concepts concerning vegetarian diet types, complementary protein, and special-care nutrients. A simple simulation gives students the opportunity to apply their knowledge in planning vegetarian diets that pro vide 100% of the RDA for calories and eight nutrients. The les son is contained on two disks; supplementary menu planning worksheets and a recipe booklet are used for off-line menu planning. The entire les son, including off-line time, takes approximately 45 minutes to complete. Study design. Fort y-four students enrolled in three independent sections of an introductory-Ievel foods and nutrition course participated in a study designed to compare the effectiveness of the CAl and the lecture/discussion method in teaching the topic of vegetarianism. We randomly designated each class section as either CAl treatment (14 students). lecture/discussion treatment (16 students), or control (14 students) groups. This research design allowed for comparison of the two instruction methods with each VOLUME
17
NUMBER
4
1985
other and with the control group. We developed pre- and posttest questionnaires for each group. Since the major thrust of many lessons in introductory-Ievel classes is to increase students' knowledge of the subject, we chose knowledge of vegetarianism as our primary criterion for evaluating lesson effectiveness. However, affective factors such as interest in the subject matter can also influence knowledge gains. Therefore, we assessed both knowledge of and interest in vegetarianism. We developed a multiple-choice test to assess knowledge of vegetarianism. Using the desired learner outcomes of the completed CAl les son, we constructed test items that reflected those outcomes (15). Nutrition and education professionals reviewed the test, and we revised test items accordingly. A panel of these professionals verified the content validity of the final 48item test. The Cronbach alpha reliability coefficient reflecting internaI consistency was 0.50 for pretest scores. The test-retest reliability coefficient for the 13 students in the control group was 0.70. To assess interest in the topic of vegetarianism, we asked students to pro vide one of three responses (slightly interested, moderately interested, or strongly interested) to the question "How interested in vegetarianism are you?" Realizing that students' previous experiences with computers might influence our results, on the posttest we asked students whether they had ever used a computer prior to class, and, if so, what kind of computer, and for what purpose. We also asked students to indicate the extent of their computer programming experience and whether they had a computer in their home. To de termine how weH students liked the CAl les son, on the posttest we asked students to de scribe their experiences with the lesson using three four-point semantic differential items: satisfying-frustrating, motivating-nonmotivating, and interesting-boring. We then calculated me an ratings for each of these items. Data collection and analysis. We conducted the study (Note 2) over a five-week period. AU three groups completed the pretest questionnaire during part of one regularly scheduled class period. One week later, we presented the CAl and lecture/discussion groups with their respective vegetarianism lessons. We gave the CAl group access to our microcomputer lab for one 3-hour class period and instructed students to progress through the lesson at a comfortable rate, but to complete aH the units. Although we remained in the computer lab, we gave no further instructions. After presenting the lecture/discussion group with a lesson that was derived From the CAl lesson, we asked questions and conducted oral exercises similar to those used in the computer lesson. We assigned a menuplanning exercise as homework, and subsequently
VOLUME
17
NUMBER
4
1985
evaluated the exercise and provided written feedback. The control group received a lesson on another topic. Three weeks after the lesson presentation, aH three groups completed the posttest questionnaires. ln tabulating and analyzing the data, we used computer programs from the Statistical Analysis System (16). We obtained descriptive statistics for aU questionnaire responses. Analysis of variance was used to determine whether pretreatment differences existed among the three groups with regard to knowledge and interest in vegetarianism, and computer experience. We also used analyses of variance to determine differences between pre- and posttest knowledge and interest in vegetarianism for each group. Table 1. Mean knowledge pre- and postscores, ± 50, of computer-assisted instruction (CAl), lecture/discussion, and control groups Mean ±SD
Group
n
Prescore 1
CAl Lecture/Discussion Control
13 11 13
32.7 ± 6.5 32.3 ± 7.1 ·34.8 ± 7.1
Postscore 37.0 35.3 34.1
± 5.1 ± 4.8 ± 7.8
lMaximum score of both the pre- and posttest = 48.
RESULTS Thirty-seven students (84%) completed both pre- and posttest questionnaires. Most of these students (84%) were female, and aH were majors in foods and nutrition options. The class is an introductory one in our curriculum; however, because of the large percent age of transfer students in our program, two-thirds (67%) of the students were classified as juniors and seniors. The CAl group had a few more males than either the lecture or control groups, but there were no differences among CAl, lecture/discussion, and control groups with respect to coHege class level. We found no significant differences among the three groups with regard to computer experience. Most of the students (92%) had previously used a computer, primarily for games (57%) and education (57%). Sorne students had used a computer for word processing (24%) and other data-management. tasks (11%). Roughly half (51%) reported they had at least sorne computer programming experience, but only 2 students had extensive experience. AU but 3 students indicated at least sorne experience with the time-sharing educational computer system used extensively on our campus. We used knowledge of vegetarianism, expressed as the total number of correct responses on the knowledge test, as our primary criteria for judging effectiveness of both instruction methods. Table 1 presents the mean prescores and post scores for students in aU three groups. Prescores on the 48-item vegetarian knowledge test were higher than we anticipated, indicating that the se
JOURNAL OF NUTRITION EDUCATION
131
Table 2. Mean pre- and posttest interest scores 1, ± SD, in vegetarianism of computer-assisted instruction (CAl), lecture/discussion, and control groups Mean ±SO Group
n
Pres core
Postscore
CAl Lecture/Discussion Control
13
11
1.9 ± .90 1.7 ± .89 1.6 ± .51
1.8 ±.73 1.8 ± .83 1.3 ± .48
13
'Responses to question "How interested in vegetarianism are you?" with 1 = slightly interested, 2 = moderately interested, and 3 = strongly interested.
students had a fair knowledge of vegetarianism even before the formaI instruction. Since there were no significant differences in prescores among the three groups, we assumed that the groups were similar in their knowledge. Although the knowledge test did not specifically address application of knowledge to planning diets, examination of individu al items on the pretest suggested that students could recall vegetarian facts and concepts more readily than they could apply them. Students were most knowledgeable about different vegetarian types and the concept of complementary protein, and least knowledgeable about nutrients of concern for various vegetarian diet types and good food sources of the se nutrients. There were no significant differences between preand postscores for any of the three groups. Nor were there any significant differences among the postscores of the three groups. Examining pre- and posttest responses for individual test items, we observed no areas of greater learning with either instructional method. Because interest in a topic can ultimately affect knowledge, we also assessed the impact of both instructional methods on interest in vegetarianism by comparing pre- and posttest responses to the question "How interested in vegetarianism are you?" On the pretest, sorne of the students (19%) were strongly interested in vegetarianism, more than a third (35%) were at least moderotely interested, and the rest (46%) were only slightly interested in this topic. Mean interest responses on pre- and posttests (Table 2) indicate that neither instructional method was particularly effective at increasing interest in this topic. During the CAl lesson, we observed that the students were attentive and seemed genuinely interested in the lesson. Table 3 presents me an ratings for the semantic differential items that CAl students used to describe their experiences with the lesson. The 11 studènts who completed these items responded positively toward the lesson. Their responses indicate that their experiences with the CAl lesson were fairly satisfying, interesting, and motivating. 132
JOURNAL OF NUTRITION EDUCATION
Table 3. Computer-assisted instruction students' mean ratings of their experiences with the vegetarianism lesson Mean Rating I ± SO
Semantic-Oifferential Item
(n
= 11)
3.5 ± .52 3.3 ±.47 3.3 ± .79
Satisfying-Frustrating Motivating-Nonmotivating Interesting-Boring
'For each item the most positive response was 4, and the least positive was 1.
DISCUSSION Due to the smaH sample size and specificity of subject matter included in the lesson, results of this study should be interpreted cautiously. They do, however, support previous research in suggesting that CAl is a feasible alternative to the lecture/discussion method in the college nutrition classroom. There were no significant effects on learning with either CAl or lecture/discussion. Although postscores on the knowledge test were not significantly higher than prescores for any of the three groups, a larger sam pIe size might have yielded significant differences. Furthermore, since students seemed relatively knowledgeable about vegetarianism even before this instruction (as evidenced by prescores), there may not have been a great deal of room for improvement. These findings are consistent with those of previous researchers. Schroeder and co-workers (3,4) compared CAl with the lecture method for the renal unit of a diet therapy course. In two separate studies, they found that CAl was as effective as traditional classroom instruction. Although student response to our CAl lesson on vegetarianism was positive, their interest in vegetarianism did not increase as a result of the lesson. Thus, their positive responses may reflect their feelings about the method of instruction rather than the topic. Other reports have also indicated that students like learning nutrition via CAL Schroeder and Kent (3) reported that the attitudes of dietetics students who learned renal diet therapy by computer were somewhat more favorable than were the attitudes of the conventionally taught students toward the lecture/ laboratory teaching method. Computer-taught students who used this renal lesson for a later study (4) were particularly enthusiastic about being in control of the learning sequence. Carew and co-workers (2) also reported positive student response to the use of CAl in nutrition education. Their preliminary evaluation of a CAl program that accompanied an introductory coHege nutrition course indicated that most students found the CAl approach useful and felt that it saved time and improved grades. VOLUME
17
NUMBER
4
1985
The results of these few studies indicate that college students taught via computer learn as much nutrition as students taught by an instructor in the more traditional lecture/discussion manner. It also seems that students like learning via computer, although their favorable responses may be at least partly due to the novelty of the learning situation. If indeed CAl is as effective as other teaching methods and if positive attitudes towards this relatively new teaching method prevail, the potential savings in both instructor and classroom time could be advantageous. College nutrition courses, particularly at the introductory level, are often large classes taught by a single instructor. Although this format is time-efficient for the instructor and thus seems cost-effective for the institution, the benefits of more personalized instruction to the student are 10s1. By using CAl as a supplement to these large classes, departments can offer individualized instruction without the increased instructional costs of small classes. Well-designed CAl tutorials on basic nutrition concepts can keep students actively involved and allow them to progress at their own pace, while providing "infinite patience" and "attention" to each student. Such tutorials can free class time for discussions of current nutrition issues, and can also be used by students to review during a course or between courses in sequence. For the se purposes CAl has advantages over printed or audiovisual materials because it is interactive, can be highly individualized, and is less costly to revise and update. It is difficult to estimate how much time can be saved by using CAL And to a great extent, the estimates will depend upon how the comparisons are made. For example, if in a class of 100 students we replace one lecture on vegetarianism with our CAl program, we will save only 1 hour of class time. However, if we consider the time it would take to provide self-paced, interactive instruction to 100 students, estimated time savings are much greater. For this study, we presented the lecture/discussion group with a les son whose content was as close as possible to the CAl lesson. Although we did not keep detailed records, we estimated that the instructor time required to pro vide this comparable lesson (to 16 students) was approxima tely 30 minutes per studen1. This estimate includes sorne time for lesson planning and presentation as well as time for evaluating student menus and providing feedback. Extrapolating to a class of 100, we estimate potential savings at roughly 50 instructor-hours per semester. We need to be realistic about these potential time savings, however. Since very few CAl programs in nutrition are currently available, instructors may need to develop their own, and the initial time costs of CAl can be very high. We spent approximately 500 hours designing and programming our vegetarianism lesson. While this amount of time seems extraordinarily high, it
VOLUME
17
NUMBER
4
1985
is consistent with estimates for other novice authors of educational programs (17). The time needed to develop a high quality CAl program varies with a number of factors including the experience of the author, the complexity of the les son, and whether the lesson makes use of existing CAl teaching strategies or generates new ones (13, 17). Since this was our first les son, we spent a considerable amount of time exploring the capabilities of CAl and generating techniques appropriate for individualized instruction. Fortunately, the time needed to produce CAl lessons generally decreases dramatically with authoring experience. Estimates of time spent by experienced authors range from 6 to 180 hours per hour of instruction depending on the nature of the lesson (17).
0
NOTES 1 For further information about the vegetarianism lesson, contact the first author at the following address: 274 Bevier Hall, 905 South Goodwin, Urbana, IL 61801. 2 This study met certain criteria for exemption from human subjects review specified by the Institutional Review Board, University of Illinois at Urbana-Champaign.
LITERATURE CITED 1 Shannon, B. Perspectives on computer use in nutrition education. Journal of Nutrition Education 16:37-38, 1984. 2 Carew, L. B., D. W. Elvin, B. A. You, and F. A. Alster. A college-Ievel, computer-assisted course in nutrition. Journal of Nutrition Education 16:46-50, 1984. 3 Schroeder, L., and P. Kent. Computer-based instruction in dietetics education. Journal of Computer-Based Instruction 8:85-90, 1982. 4 Schroeder, L., and D. Driscoll. Computerized learning for clinical and nonclinical students. Journal of the American Dietetic Association 83:163-66, 1983. 5 Maruyama, F. T., and J. D. Forester. Programs with color, sound, and graphies. Journal of Nutrition Education 16:57, 1984. 6 Duford, S., J. S. Payne, and K. H. Timmons. Computer use in a nutrition course for elementary education majors. Journal of Nutrition Education 16:76B, 1984. 7 Murphy, S. P., J. C. King, and D. H. Calloway. Choosing a diet analysis system for classroom use. Journal of Nutrition Education 16:73-75, 1984. 8 Slavin, J. L., M. E. Darling, and M. L. Mattson. Computer experiences in food and nutrition cooperative extension programs. Journal of Nutrition Education 16:70-72, 1984. 9 Smiciklas-Wright, H., S. Pelican, C. Byrd-Bredbenner, and B. Shannon. Clients' comprehension of a computeranalyzed dietary intake prin tout. Journal of Nutrition Education 16:67-69, 1984. 10 Conklin, D. N. A study of computer-assisted instruction in nursing education. Journal of Computer-Based Instruction 9:98-107, 1983. 11 Fisher, G. Where CAl is effective-A summary of the research. Electronic Learning 3:82-84, 1983.
JOURNAL OF NUTRITION EDUCATION
133
12 Kulik, J. A, C. C. Kulik, and P. A Cohen. Effectiveness of computer-based college teaching-A meta-analysis of findings. Review of Educational Research 50:525-44, 1980. 13 Steinberg, E. R. Teaching computers to teach. Hillsdale, NJ: Lawrence Erlbaum, 1984, 208 pp. 14 Ries, C. P., J. Granell, and P. Zemel. Authoring a CAl les son in nutrition education. Journal of Nutrition Education 16:51-52, 1984. 15 Gronlund, N. E. Measurement and evaluation in teaching,
3d ed. New York: Macmillan Publishing Co., Inc., 1976, pp. 28-78. 16 Blair, W., R. Cross, D. Ingold, and C. Whitman. Statistical analysis systems users guide, Raleigh, NC: Reinhardt Inc., 1979, 494 pp. 17 Avner, R. A Production of computer-based instructional materials. In Issues in instructional systems development, H. F. O'Neil, Jr., ed. New York: Academic Press, Inc., 1979, pp. 133-80.
A COMPARISON OF TWO VERY LOW-CALORIE DIETS Researchers continue to investigate the effect of very low-calorie (VLC) diets. At present, there are two types of VLC diets. There is the protein-sparing-modified fast (PSMF) in which the protein is obtained directly from lean meat, fish, and fowl. In this diet carbohydrate is prohibited, and fat is restricted to the amount that is in the protein source. The other type of VLC diet is commercially prepared liquid protein formulas-milk- or eggbased. Both types provide 300 to 400 kcal daily, and both must be supplemented with vitamins and mineraIs. A recent study by Wadden et al. (American Journal of Clinical Nutrition 41:533-39, 1985) investigated the acceptability of the two regimens and their respective abilities to satisfy hunger. Sixteen moderately overweight subjects were first prescribed a 1000-1200 kcal balanced diet for four weeks. Then they were randomly assigned to a PSMF or liquid diet for another four-week period. Subjects completed appetite and mood scales on a weekly basis throughout the study. Although both diets resulted in comparable weight loss, the researchers concluded that the PSMF may have several advantages over the liquid formula diet. For example, in comparison with the baseline ratings obtained on the 1000-1200 kcal diets, PSMF subjects reported significantly less hunger and preoccupation with food during two of the four weeks, and liquid diet subjects reported slightly (but not significantly) more hunger and preoccupation with food during the same two weeks. PSMF subjects also tended to like their VLC diet as much as the preceding 1200 kcal diet, while liquid diet subjects liked their diet significantly less. The cause of the se effects is not known, but Wadden et al. suggested that a possible explanation concerns differences in the taste, texture, and temperature of the diets. Liquid diet subjects complained of the lack of hot chewable food and the monotony of the diet. Such corn plaints were less intense among PSMF subjects who chose their meals from 15 different servings of animal protein that were consumed either hot or cold. Although the researchers stressed the possible advantages of the PSMF, they also pointed out that their work do es not indicate whether the PSMF would retain its advantages over the liquid diet for more than a few weeks. They called for further research to determine the possibility of long-term advantages.
RECENT REVIEWS ON FLUORIDATION AND ON INFANT FEEDING Recent issues of theAmerican Journal of CJinical Nutrition contain information that will likely be of interest to JNE readers. The January issue contains a review of fluoridation and fluoride use. This article, by V.L. Richmond (41:129-38, 1985) covers topics such as effectiveness, intake, therapeutic uses, and safety. The February issue is a supplement (41:381-509, 1985) entitled "Workshop on Introduction of Food to Infants." The workshop, held in February 1983, was sponsored by the International Organization for the Study of Human Development. Editors for the supplement are Drs. Frank Falker and Norman Kretchmer. The 14 articles included in the supplement are grouped into biological and physiological considerations, nutritional considerations, and general considerations. 134
JOURNAL OF NUTRITION EDUCATION
VOLUME
17
NUMBER
4
1985
P.
RIES AND JULIE GRANELL
Department of Foods and Nutrition, University of Illinois, Urbana, Illinois 61801 ABSTRACT' We developed a college-level computerassisted instruction (CAl) les son on vegetarianism and compared its effectiveness with the lecture/discussion method. Our independent CAl lesson consists of tutorial and drill-andpractice routines and a simple diet planning simulation. We collected pretest and posttest data on knowledge of and interest in vegetarianism from 44 students in an introductory foods and nutrition class. We randomly assigned three sections to receive either the CAl lesson, a comparable discussion lesson, or a lesson on another topic. There were no significant differences among these three groups either in pre- or posttest knowledge scores, or in interest in vegetarianism. CAl students' responses to learning by computer were positive. We discuss the potential savings in instructor and classroom time that may make CAl use advantageous as a substitute or (JNE 17:130-34, 1985) supplement to classroom teaching.
The increasing availability of computers and nutrition-related software has stimulated interest in the use of computer-assisted instruction (CAl) in nutrition education (1). Recent literature reports of computer applications in nutrition education include the use of CAl for college-Ievel introductory nutrition and diet therapy students (2-4) and for the general public in shopping malIs or fairs (5). as weIl as the use of computerized dietary analysis in various educational settings (6-9). However, most of these reports are descriptions of specific experiences and viewpoints of the educators involved. And while these reports stimulate further interest in CAl, research on its comparative effectiveness as an instructional method is needed to justify its widespread use in nutrition education (1). Research in many subject matter areas (10-12) has shown that CAl can be effective; however, thus far there has been little research on the effectiveness of CAl in nutrition education. This CAl evaluation project emerged from our concern over the lack of classroom time that was available to examine certain nutrition topics in our introductory college courses. Consequently, we hoped to de termine whether CAl was a feasible alternative to the lecture/discussion method for teaching foods and nutrition topics at the introductory college level. SpecificaIly, we sought to compare the effectiveness of our CAl vegetarianism lesson with the lecture/ discussion method. 130
JOURNAL OF NUTRITION EDUCATION
METHODS Computer les son development. FolIowing recommended design principles and procedures (13), we developed a lesson on the topic of vegetarianism for introductory-Ievel college students (Note 1). In a previous article (14), we have described the process that we used to design and develop the lesson and have presented our judgments concerning the feasibility of nutrition educators developing their own software. We chose vegetarianism as our topic for two reasons. First, although college students are frequently interested in this topic, in our curriculum, instruction in vegetarianism is often considered expendable due to constraints in class time. Second, sorne topics are more appropria te than others for interactive computer instruction. For example, if a topic is too complex or broad, a lesson with adequate interaction may require an unreasonable amount of user time (13). We felt that the relatively straightforward principles of vegetarianism could be presented in an interactive style within a reasonable amount of instruction time. Our vegetarianism lesson is designed for independent study on a microcomputer. Tutorial, and drill-andpractice routines present facts and concepts concerning vegetarian diet types, complementary protein, and special-care nutrients. A simple simulation gives students the opportunity to apply their knowledge in planning vegetarian diets that pro vide 100% of the RDA for calories and eight nutrients. The les son is contained on two disks; supplementary menu planning worksheets and a recipe booklet are used for off-line menu planning. The entire les son, including off-line time, takes approximately 45 minutes to complete. Study design. Fort y-four students enrolled in three independent sections of an introductory-Ievel foods and nutrition course participated in a study designed to compare the effectiveness of the CAl and the lecture/discussion method in teaching the topic of vegetarianism. We randomly designated each class section as either CAl treatment (14 students). lecture/discussion treatment (16 students), or control (14 students) groups. This research design allowed for comparison of the two instruction methods with each VOLUME
17
NUMBER
4
1985
other and with the control group. We developed pre- and posttest questionnaires for each group. Since the major thrust of many lessons in introductory-Ievel classes is to increase students' knowledge of the subject, we chose knowledge of vegetarianism as our primary criterion for evaluating lesson effectiveness. However, affective factors such as interest in the subject matter can also influence knowledge gains. Therefore, we assessed both knowledge of and interest in vegetarianism. We developed a multiple-choice test to assess knowledge of vegetarianism. Using the desired learner outcomes of the completed CAl les son, we constructed test items that reflected those outcomes (15). Nutrition and education professionals reviewed the test, and we revised test items accordingly. A panel of these professionals verified the content validity of the final 48item test. The Cronbach alpha reliability coefficient reflecting internaI consistency was 0.50 for pretest scores. The test-retest reliability coefficient for the 13 students in the control group was 0.70. To assess interest in the topic of vegetarianism, we asked students to pro vide one of three responses (slightly interested, moderately interested, or strongly interested) to the question "How interested in vegetarianism are you?" Realizing that students' previous experiences with computers might influence our results, on the posttest we asked students whether they had ever used a computer prior to class, and, if so, what kind of computer, and for what purpose. We also asked students to indicate the extent of their computer programming experience and whether they had a computer in their home. To de termine how weH students liked the CAl les son, on the posttest we asked students to de scribe their experiences with the lesson using three four-point semantic differential items: satisfying-frustrating, motivating-nonmotivating, and interesting-boring. We then calculated me an ratings for each of these items. Data collection and analysis. We conducted the study (Note 2) over a five-week period. AU three groups completed the pretest questionnaire during part of one regularly scheduled class period. One week later, we presented the CAl and lecture/discussion groups with their respective vegetarianism lessons. We gave the CAl group access to our microcomputer lab for one 3-hour class period and instructed students to progress through the lesson at a comfortable rate, but to complete aH the units. Although we remained in the computer lab, we gave no further instructions. After presenting the lecture/discussion group with a lesson that was derived From the CAl lesson, we asked questions and conducted oral exercises similar to those used in the computer lesson. We assigned a menuplanning exercise as homework, and subsequently
VOLUME
17
NUMBER
4
1985
evaluated the exercise and provided written feedback. The control group received a lesson on another topic. Three weeks after the lesson presentation, aH three groups completed the posttest questionnaires. ln tabulating and analyzing the data, we used computer programs from the Statistical Analysis System (16). We obtained descriptive statistics for aU questionnaire responses. Analysis of variance was used to determine whether pretreatment differences existed among the three groups with regard to knowledge and interest in vegetarianism, and computer experience. We also used analyses of variance to determine differences between pre- and posttest knowledge and interest in vegetarianism for each group. Table 1. Mean knowledge pre- and postscores, ± 50, of computer-assisted instruction (CAl), lecture/discussion, and control groups Mean ±SD
Group
n
Prescore 1
CAl Lecture/Discussion Control
13 11 13
32.7 ± 6.5 32.3 ± 7.1 ·34.8 ± 7.1
Postscore 37.0 35.3 34.1
± 5.1 ± 4.8 ± 7.8
lMaximum score of both the pre- and posttest = 48.
RESULTS Thirty-seven students (84%) completed both pre- and posttest questionnaires. Most of these students (84%) were female, and aH were majors in foods and nutrition options. The class is an introductory one in our curriculum; however, because of the large percent age of transfer students in our program, two-thirds (67%) of the students were classified as juniors and seniors. The CAl group had a few more males than either the lecture or control groups, but there were no differences among CAl, lecture/discussion, and control groups with respect to coHege class level. We found no significant differences among the three groups with regard to computer experience. Most of the students (92%) had previously used a computer, primarily for games (57%) and education (57%). Sorne students had used a computer for word processing (24%) and other data-management. tasks (11%). Roughly half (51%) reported they had at least sorne computer programming experience, but only 2 students had extensive experience. AU but 3 students indicated at least sorne experience with the time-sharing educational computer system used extensively on our campus. We used knowledge of vegetarianism, expressed as the total number of correct responses on the knowledge test, as our primary criteria for judging effectiveness of both instruction methods. Table 1 presents the mean prescores and post scores for students in aU three groups. Prescores on the 48-item vegetarian knowledge test were higher than we anticipated, indicating that the se
JOURNAL OF NUTRITION EDUCATION
131
Table 2. Mean pre- and posttest interest scores 1, ± SD, in vegetarianism of computer-assisted instruction (CAl), lecture/discussion, and control groups Mean ±SO Group
n
Pres core
Postscore
CAl Lecture/Discussion Control
13
11
1.9 ± .90 1.7 ± .89 1.6 ± .51
1.8 ±.73 1.8 ± .83 1.3 ± .48
13
'Responses to question "How interested in vegetarianism are you?" with 1 = slightly interested, 2 = moderately interested, and 3 = strongly interested.
students had a fair knowledge of vegetarianism even before the formaI instruction. Since there were no significant differences in prescores among the three groups, we assumed that the groups were similar in their knowledge. Although the knowledge test did not specifically address application of knowledge to planning diets, examination of individu al items on the pretest suggested that students could recall vegetarian facts and concepts more readily than they could apply them. Students were most knowledgeable about different vegetarian types and the concept of complementary protein, and least knowledgeable about nutrients of concern for various vegetarian diet types and good food sources of the se nutrients. There were no significant differences between preand postscores for any of the three groups. Nor were there any significant differences among the postscores of the three groups. Examining pre- and posttest responses for individual test items, we observed no areas of greater learning with either instructional method. Because interest in a topic can ultimately affect knowledge, we also assessed the impact of both instructional methods on interest in vegetarianism by comparing pre- and posttest responses to the question "How interested in vegetarianism are you?" On the pretest, sorne of the students (19%) were strongly interested in vegetarianism, more than a third (35%) were at least moderotely interested, and the rest (46%) were only slightly interested in this topic. Mean interest responses on pre- and posttests (Table 2) indicate that neither instructional method was particularly effective at increasing interest in this topic. During the CAl lesson, we observed that the students were attentive and seemed genuinely interested in the lesson. Table 3 presents me an ratings for the semantic differential items that CAl students used to describe their experiences with the lesson. The 11 studènts who completed these items responded positively toward the lesson. Their responses indicate that their experiences with the CAl lesson were fairly satisfying, interesting, and motivating. 132
JOURNAL OF NUTRITION EDUCATION
Table 3. Computer-assisted instruction students' mean ratings of their experiences with the vegetarianism lesson Mean Rating I ± SO
Semantic-Oifferential Item
(n
= 11)
3.5 ± .52 3.3 ±.47 3.3 ± .79
Satisfying-Frustrating Motivating-Nonmotivating Interesting-Boring
'For each item the most positive response was 4, and the least positive was 1.
DISCUSSION Due to the smaH sample size and specificity of subject matter included in the lesson, results of this study should be interpreted cautiously. They do, however, support previous research in suggesting that CAl is a feasible alternative to the lecture/discussion method in the college nutrition classroom. There were no significant effects on learning with either CAl or lecture/discussion. Although postscores on the knowledge test were not significantly higher than prescores for any of the three groups, a larger sam pIe size might have yielded significant differences. Furthermore, since students seemed relatively knowledgeable about vegetarianism even before this instruction (as evidenced by prescores), there may not have been a great deal of room for improvement. These findings are consistent with those of previous researchers. Schroeder and co-workers (3,4) compared CAl with the lecture method for the renal unit of a diet therapy course. In two separate studies, they found that CAl was as effective as traditional classroom instruction. Although student response to our CAl lesson on vegetarianism was positive, their interest in vegetarianism did not increase as a result of the lesson. Thus, their positive responses may reflect their feelings about the method of instruction rather than the topic. Other reports have also indicated that students like learning nutrition via CAL Schroeder and Kent (3) reported that the attitudes of dietetics students who learned renal diet therapy by computer were somewhat more favorable than were the attitudes of the conventionally taught students toward the lecture/ laboratory teaching method. Computer-taught students who used this renal lesson for a later study (4) were particularly enthusiastic about being in control of the learning sequence. Carew and co-workers (2) also reported positive student response to the use of CAl in nutrition education. Their preliminary evaluation of a CAl program that accompanied an introductory coHege nutrition course indicated that most students found the CAl approach useful and felt that it saved time and improved grades. VOLUME
17
NUMBER
4
1985
The results of these few studies indicate that college students taught via computer learn as much nutrition as students taught by an instructor in the more traditional lecture/discussion manner. It also seems that students like learning via computer, although their favorable responses may be at least partly due to the novelty of the learning situation. If indeed CAl is as effective as other teaching methods and if positive attitudes towards this relatively new teaching method prevail, the potential savings in both instructor and classroom time could be advantageous. College nutrition courses, particularly at the introductory level, are often large classes taught by a single instructor. Although this format is time-efficient for the instructor and thus seems cost-effective for the institution, the benefits of more personalized instruction to the student are 10s1. By using CAl as a supplement to these large classes, departments can offer individualized instruction without the increased instructional costs of small classes. Well-designed CAl tutorials on basic nutrition concepts can keep students actively involved and allow them to progress at their own pace, while providing "infinite patience" and "attention" to each student. Such tutorials can free class time for discussions of current nutrition issues, and can also be used by students to review during a course or between courses in sequence. For the se purposes CAl has advantages over printed or audiovisual materials because it is interactive, can be highly individualized, and is less costly to revise and update. It is difficult to estimate how much time can be saved by using CAL And to a great extent, the estimates will depend upon how the comparisons are made. For example, if in a class of 100 students we replace one lecture on vegetarianism with our CAl program, we will save only 1 hour of class time. However, if we consider the time it would take to provide self-paced, interactive instruction to 100 students, estimated time savings are much greater. For this study, we presented the lecture/discussion group with a les son whose content was as close as possible to the CAl lesson. Although we did not keep detailed records, we estimated that the instructor time required to pro vide this comparable lesson (to 16 students) was approxima tely 30 minutes per studen1. This estimate includes sorne time for lesson planning and presentation as well as time for evaluating student menus and providing feedback. Extrapolating to a class of 100, we estimate potential savings at roughly 50 instructor-hours per semester. We need to be realistic about these potential time savings, however. Since very few CAl programs in nutrition are currently available, instructors may need to develop their own, and the initial time costs of CAl can be very high. We spent approximately 500 hours designing and programming our vegetarianism lesson. While this amount of time seems extraordinarily high, it
VOLUME
17
NUMBER
4
1985
is consistent with estimates for other novice authors of educational programs (17). The time needed to develop a high quality CAl program varies with a number of factors including the experience of the author, the complexity of the les son, and whether the lesson makes use of existing CAl teaching strategies or generates new ones (13, 17). Since this was our first les son, we spent a considerable amount of time exploring the capabilities of CAl and generating techniques appropriate for individualized instruction. Fortunately, the time needed to produce CAl lessons generally decreases dramatically with authoring experience. Estimates of time spent by experienced authors range from 6 to 180 hours per hour of instruction depending on the nature of the lesson (17).
0
NOTES 1 For further information about the vegetarianism lesson, contact the first author at the following address: 274 Bevier Hall, 905 South Goodwin, Urbana, IL 61801. 2 This study met certain criteria for exemption from human subjects review specified by the Institutional Review Board, University of Illinois at Urbana-Champaign.
LITERATURE CITED 1 Shannon, B. Perspectives on computer use in nutrition education. Journal of Nutrition Education 16:37-38, 1984. 2 Carew, L. B., D. W. Elvin, B. A. You, and F. A. Alster. A college-Ievel, computer-assisted course in nutrition. Journal of Nutrition Education 16:46-50, 1984. 3 Schroeder, L., and P. Kent. Computer-based instruction in dietetics education. Journal of Computer-Based Instruction 8:85-90, 1982. 4 Schroeder, L., and D. Driscoll. Computerized learning for clinical and nonclinical students. Journal of the American Dietetic Association 83:163-66, 1983. 5 Maruyama, F. T., and J. D. Forester. Programs with color, sound, and graphies. Journal of Nutrition Education 16:57, 1984. 6 Duford, S., J. S. Payne, and K. H. Timmons. Computer use in a nutrition course for elementary education majors. Journal of Nutrition Education 16:76B, 1984. 7 Murphy, S. P., J. C. King, and D. H. Calloway. Choosing a diet analysis system for classroom use. Journal of Nutrition Education 16:73-75, 1984. 8 Slavin, J. L., M. E. Darling, and M. L. Mattson. Computer experiences in food and nutrition cooperative extension programs. Journal of Nutrition Education 16:70-72, 1984. 9 Smiciklas-Wright, H., S. Pelican, C. Byrd-Bredbenner, and B. Shannon. Clients' comprehension of a computeranalyzed dietary intake prin tout. Journal of Nutrition Education 16:67-69, 1984. 10 Conklin, D. N. A study of computer-assisted instruction in nursing education. Journal of Computer-Based Instruction 9:98-107, 1983. 11 Fisher, G. Where CAl is effective-A summary of the research. Electronic Learning 3:82-84, 1983.
JOURNAL OF NUTRITION EDUCATION
133
12 Kulik, J. A, C. C. Kulik, and P. A Cohen. Effectiveness of computer-based college teaching-A meta-analysis of findings. Review of Educational Research 50:525-44, 1980. 13 Steinberg, E. R. Teaching computers to teach. Hillsdale, NJ: Lawrence Erlbaum, 1984, 208 pp. 14 Ries, C. P., J. Granell, and P. Zemel. Authoring a CAl les son in nutrition education. Journal of Nutrition Education 16:51-52, 1984. 15 Gronlund, N. E. Measurement and evaluation in teaching,
3d ed. New York: Macmillan Publishing Co., Inc., 1976, pp. 28-78. 16 Blair, W., R. Cross, D. Ingold, and C. Whitman. Statistical analysis systems users guide, Raleigh, NC: Reinhardt Inc., 1979, 494 pp. 17 Avner, R. A Production of computer-based instructional materials. In Issues in instructional systems development, H. F. O'Neil, Jr., ed. New York: Academic Press, Inc., 1979, pp. 133-80.
A COMPARISON OF TWO VERY LOW-CALORIE DIETS Researchers continue to investigate the effect of very low-calorie (VLC) diets. At present, there are two types of VLC diets. There is the protein-sparing-modified fast (PSMF) in which the protein is obtained directly from lean meat, fish, and fowl. In this diet carbohydrate is prohibited, and fat is restricted to the amount that is in the protein source. The other type of VLC diet is commercially prepared liquid protein formulas-milk- or eggbased. Both types provide 300 to 400 kcal daily, and both must be supplemented with vitamins and mineraIs. A recent study by Wadden et al. (American Journal of Clinical Nutrition 41:533-39, 1985) investigated the acceptability of the two regimens and their respective abilities to satisfy hunger. Sixteen moderately overweight subjects were first prescribed a 1000-1200 kcal balanced diet for four weeks. Then they were randomly assigned to a PSMF or liquid diet for another four-week period. Subjects completed appetite and mood scales on a weekly basis throughout the study. Although both diets resulted in comparable weight loss, the researchers concluded that the PSMF may have several advantages over the liquid formula diet. For example, in comparison with the baseline ratings obtained on the 1000-1200 kcal diets, PSMF subjects reported significantly less hunger and preoccupation with food during two of the four weeks, and liquid diet subjects reported slightly (but not significantly) more hunger and preoccupation with food during the same two weeks. PSMF subjects also tended to like their VLC diet as much as the preceding 1200 kcal diet, while liquid diet subjects liked their diet significantly less. The cause of the se effects is not known, but Wadden et al. suggested that a possible explanation concerns differences in the taste, texture, and temperature of the diets. Liquid diet subjects complained of the lack of hot chewable food and the monotony of the diet. Such corn plaints were less intense among PSMF subjects who chose their meals from 15 different servings of animal protein that were consumed either hot or cold. Although the researchers stressed the possible advantages of the PSMF, they also pointed out that their work do es not indicate whether the PSMF would retain its advantages over the liquid diet for more than a few weeks. They called for further research to determine the possibility of long-term advantages.
RECENT REVIEWS ON FLUORIDATION AND ON INFANT FEEDING Recent issues of theAmerican Journal of CJinical Nutrition contain information that will likely be of interest to JNE readers. The January issue contains a review of fluoridation and fluoride use. This article, by V.L. Richmond (41:129-38, 1985) covers topics such as effectiveness, intake, therapeutic uses, and safety. The February issue is a supplement (41:381-509, 1985) entitled "Workshop on Introduction of Food to Infants." The workshop, held in February 1983, was sponsored by the International Organization for the Study of Human Development. Editors for the supplement are Drs. Frank Falker and Norman Kretchmer. The 14 articles included in the supplement are grouped into biological and physiological considerations, nutritional considerations, and general considerations. 134
JOURNAL OF NUTRITION EDUCATION
VOLUME
17
NUMBER
4
1985