thesisAs case-based learning (CBL) via computer-assisted instruction becomes a burgeoning instructional method within medical education, its pedagogical value must be ascertained. In particular, the relative efficacy of specific instructional elements that comprise the CBL methodology must be determined. For example, numerous laboratory studies have proposed conditions that may facilitate knowledge transfer via analogy (case-based reasoning). However, few of these methods have been evaluated in complex learning environments such as medicine. The study included in this thesis, The Medulator™ Analogical Reasoning Study"" (MARS), employed an online patient simulation application to evaluate several potential methods for the optimization of learning by clinical novices (i.e., medical students). Medulator™, a commercial Web-based patient simulation application, was modified to test the effects of case sequencing, explicit case comparison, and user-generated case summaries on user performance. Senior medical students self-enrolled via the Internet and were randomized to complete analogous sets of virtual patient cases in different sequences, with or without an explicit analogical reasoning exercise being invoked for analogous case pairs and with or without the ability to generate user-authored case summaries. Specific aspects of their case performance were then tracked. A brief follow-up user survey was conducted to determine overall satisfaction with the online CBL approach and to determine perceived value of the analogical reasoning component. A significant effect of case sequencing on analogy transfer was seen only with respect to correct treatment scores (p = .009). Explicit case comparison had no reliable effect on performance. However, diagnostic accuracy increased (p = .002) while treatment attempts decreased (p = .05) when subjects were prompted to write case summaries. The additional time needed to write case summaries was not statistically significant (p = .12). Overall, user satisfaction with the Medulator™ was excellent. However, high perceived value of the analogical reasoning component was not supported by measured results. Manipulating case sequences and supporting explicit case comparison yielded mixed results, suggesting that these methods afford instructional value only under specific learning conditions. However, using case summaries as a tool for reflection and proxy for self-explanation led to significant early and sustained improvement in students' performance."
