Designing cases in problem-based learning to foster problem-solving skill.

The purpose of this study was to examine the effect of case segmentation schemes in problem-based learning (PBL) on the development of problem-solving skill, self-directedness and technical knowledge. Seventy-four dental education students were randomly assigned to 12 PBL groups. Six groups experienced PBL cases that were formatted in short segments and six groups experienced PBL cases that were formatted in long segments. Pretest measures of problem-solving skill, self-directedness and technical knowledge were administered at the beginning of the Fall 1998 semester. Students studied three PBL cases in their assigned groups in the ensuing semester. Posttest measures were administered at the conclusion of the semester. Analysis of the data found that students who experienced PBL with a short case segmentation scheme were better able to solve problems highly similar to the problems in the teaching cases than students who experienced PBL with a long case segmentation scheme. No significant differences were found for self-directedness, technical knowledge, or ability to solve problems distinctly different from the teaching cases. Explanations of these findings and their implications for research and practice in PBL are discussed.