Multiple choice questions as a single tool for assessing retention of knowledge in problem-based learning

ABSTRACT

To test if traditional multiple-choice-questions [MCQ] can be used in evaluating the retention of knowledge by two methods, problem-based learning [PBL] and lecture-based learning [LBL]. Design: An observational study. Place and Duration of Study The study was conducted at the Dow Medical College over a period of eight months. Subjects and All 249 second year medical students attending classes were included and taught a topic of biochemistry by the LBL method. Among these students 141 were then taught another topic of biochemistry by a PBL method. A traditional MCQ test was conducted at the conclusion of each topic. Five months later, they were given a specially-designed questionnaire to find their own retention of knowledge by each method. The same two MCQ tests were repeated. Students' self-assessment was compared for both the methods by the Wilcoxon Signed-Rank test for matched samples. Paired t-test for mean MCQ scores was done to compare their scores at 0 and 5 months. No significant difference was found between their mean scores at 0 months by the PBL or LBL methods but after five months, the retest score showed that the material taught by LBL was retained more [though not significantly] than that taught by PBL, although by the students own assessment, retention by PBL was thought to be significantly higher than by LBL [p = 0.001]. There was a discrepancy between the students self-assessment of retention of knowledge and that elicited by the traditional MCQs. Thus, traditional MCQs cannot be used as a sole evaluation tool for retention of knowledge by PBL