The effect of teaching method on long-term knowledge retention.

Choosing a teaching strategy that results in knowledge retention on the part of learners can be challenging for educators. Studies on problem-based learning (PBL) have supported its effectiveness, compared to other, more traditional strategies. The results of a previous study comparing the effect of lecture versus PBL on objective test scores indicated there was no significant difference in scores. To measure long-term knowledge retention, the same groups were evaluated 1 year after instruction. The posttest administered in the original study was repeated, and the scores from a comprehensive adult health examination and the endocrine subsection were analyzed. At an alpha level of 0.05, a statistically significant difference was found in the scores on two of the measures. The scores of the PBL group were significantly higher on the endocrine section of the examination and the repeat posttest.