Assessing the measurement properties of a clinical reasoning exercise

Background: A challenge for Problem-Based Leaming (PBL) schools is to intro duce reliable, valid, and cost-effective testing methods into the curriculu m in such a way as to maximize the potential benefits of PBL while avoiding problems associated with assessment techniques like multiple-choice questi on, or MCQ tests. Purpose: We document the continued development of an exam that was designed to satisfy the demands of both PBL and the scientific principles of measur ement. Methods: A total of 102 medical students wrote a clinical reasoning exercis e (CRE) as a requirement for two consecutive units of instruction. Each CRE consisted of a series of 18 short clinical problems designed to assess a s tudent's knowledge of the mechanism of diseases that were covered in three subunits located within each unit. Responses were scored by a student's tut or and a 2nd crossover tutor. Results: Generalizability coefficients for raters, subunits, and individual problems were low, but the reliability of the overall test scores and the reliability of the scores across 2 units of instruction were high. Subseque nt analyses found that the crossover tutor's ratings were lower than the ra tings provided by one's own tutor and the CRE correlated with the biology c omponent of a progress test. Conclusion: The magnitude of the generalizability coefficients demonstrates that the CRE is capable of detecting differences in reasoning across knowl edge domains and is therefore a useful evaluation tool.