Journal of School of Public Health and

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Many studies indicate that the nutritional knowledge and practice of adolescent girls are inadequate. Few surveys were performanced about effect of nutrition education on knowledge, attitude and practice in this vulnerable group. The purpose of this study was to compare the effect of two nutrition education methods (guidebook and group discussion) on the nutritional knowledge, attitude and practice of first-grade guidance school girl students in Tehran ’s 8th district, in 2003.A total of 300 students were selected from 11 guidance schools by simple random sampling and divided into three 100-student groups: 1-guide-book, 2-group discussion, and 3-control. Data on the nutritional knowledge, attitude and practice were collected using pretest and posttest questionnaires. The students in group1 were given the guide-book and required to study it at home, while group 2 students were told to discuss among themselves the contents of the guide-book. The control group were given nothing to study or to do. The pre-test showed that the mean scores of nutrition knowledge (K), attitude (A) and practice (P) were not statistically different among the 3 groups. The scores for the 3 variables increased in the guide-book and discussion groups significantly at the end of the study period (in all cases, p<0.001), while the inter-group comparisons also showed that the K and A scores were statistically different among the 3 groups the P, however, was not different among them. Conclusion: Both methods (guide-book and group discussion)increased the level of nutritional knowledge and attitude as compared to (a) – the control group,and (b) – the initial values. Also both methods increased the level of nutritional practice as compared to (b) – the initial values. The group discussion method was more effective than the guide-book method in the promotion of the nutritional knowledge of the students.

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Background and Aim: The objective of this study was to assess the psychometric properties of the Adolescent Depression Scale (ADS) based on the item-response theory and compare the results with those based on the classic test theory.

Materials and Methods: A total of 750 students (364 males and 386 females) were selected through multistage random clustering (levels proportional to size) and completed a questionnaire comprising 46 questions developed by the investigators.

Results: Results of factor analysis and questions structure showed that the important item-response theory presumptions, namely, unidimensionality and local independence, are contained in ADS. As regards the psychometric characteristics of the questions, results from the two theories were similar, except that the item-response theory provided more valid indices for assessing the questions. Further analysis of the data indicated that the two theories showed close values for internal consistency with regard to psychometric characteristics, such that values of 0.933 and 0.947 were obtained for Alpha Cronbach and marginal validity, respectively. Finally, the normality scores were calculated based on the Item Response Theory with those based on the Classic Test Theory. Ranking the individuals by the two theories showed considerable differences as regards the depression construct continuum, such as a difference of 86, 92, or 93 individuals.

Conclusions: Based on the findings, it can be concluded that the item-response theory models provides a higher number of more exact indices for judgment and making decisions about questions, tests and individual ranking. Therefore, application of the item-response theory for assessment of other educational and psychological constructs is recommended.