Exploratory factor analysis of students' ratings of a problem-based learning curriculum.

PURPOSE: To identify the factor structure underlying medical students' initial experience with a problem-based learning (PBL) curriculum and to examine the stability of this structure as students acquire further experience with PBL. METHOD: The PBL curriculum at the Michigan State University College of Human Medicine begins in the students' second year and is divided into 11 domains. In 1992-93 students were asked to evaluate their learning experiences in the first and last domains of their first PBL semester, by using a five-point Likert scale to rate 19 items. Principal-components analysis and varimax rotation were used to identify the factors underlying the students' ratings. RESULTS: Ratings of the first and last domains were available from 101 and 71 students, respectively. Analysis yielded four meaningful factors: learning materials, small-group process, tutor effectiveness, and academic support. These four factors shifted in relative importance as the students progressed through the curriculum: for the first domain, tutor effectiveness accounted for the highest percentage of variance in the data; for the last domain, this factor ranked third, after learning materials and small group process. Internal reliabilities for the ratings of the last domain of the semester were higher and more consistent, ranging from .92 to .97. CONCLUSION: The students' initial dependence on the tutor progressed to an emphasis on learning resources. This shift is congruent with the theoretical model of the dynamics of PBL. The results suggest that the survey instrument provides a reliable measure of the multidimensional constructs underlying students' experience with PBL.

Gender bias in the measurement properties of the Center for Epidemiologic Studies Depression Scale (CES-D).

Confirmatory factor-analytic models are used to examine gender biases of individual items of the Center for Epidemiologic Studies Depression (CES-D) Scale. In samples containing 708 cancer patients and 504 caregivers of the chronically ill elderly, two CES-D items are identified as producing biased responses in comparisons of male and female respondents. Three additional CES-D items are excluded on the basis of other psychometric problems, yielding a subset of 15 CES-D items that capture almost all the information of the original 20-item CES-D scale but are free of any gender bias. Gender differences in mean levels of depressive symptomatology are significantly reduced, but not eliminated, when the 15-item scale is used.