Influence of PBL with open-book tests on knowledge retention measured with progress tests

M. Heijne-Penninga*, J. B. M. Kuks, W. H. A. Hofman, A. M. M. Muijtjens, J. Cohen-Schotanus

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


The influence of problem-based learning (PBL) and open-book tests on long-term knowledge retention is unclear and subject of discussion. Hypotheses were that PBL as well as open-book tests positively affect long-term knowledge retention. Four progress test results of fifth and sixth-year medical students (n = 1,648) of three medical schools were analyzed. Two schools had PBL driven curricula, and the third one had a traditional curriculum (TC). One of the PBL schools (PBLob) used a combination of open-book (assessing backup knowledge) and closed-book tests (assessing core knowledge); the other two schools (TC and PBLcb) only used closed-book tests. The items of the progress tests were divided into core and backup knowledge. T tests (with Bonferroni correction) were used to analyze differences between curricula. PBL students performed significantly better than TC students on core knowledge (average effect size (av ES) = 0.37-0.74) and PBL students tested with open-book tests scored somewhat higher than PBL students tested without such tests (av ES = 0.23-0.30). Concerning backup knowledge, no differences were found between the scores of the three curricula. Students of the two PBL curricula showed a substantially better long-term knowledge retention than TC students. PBLob students performed somewhat better on core knowledge than PBLcb students. These outcomes suggest that a problem-based instructional approach in particular can stimulate long-term knowledge retention. Distinguishing knowledge into core and backup knowledge and using open-book tests alongside closed-book tests could enhance long-term core knowledge retention.
Original languageEnglish
Pages (from-to)485-495
JournalAdvances in Health Sciences Education
Issue number3
Publication statusPublished - Aug 2013


  • Assessment
  • Knowledge
  • Open-book tests
  • PBL
  • Retention

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