Case based learning with worked examples in medicine: effects of errors and feedback

To facilitate medical students’ diagnostic knowledge a case-based worked example approach was realized in a complex computer-based learning environment. To enhance the effectiveness of the approach the measures erroneous examples and elaborated feedback were additionally implemented. 153 medical students were randomly assigned to four experimental conditions of a 2x2-factorial design (errors vs. no errors, elaborated feedback vs. knowledge of correct result (KOR)). In order to assess the sustainability of the learning environment a subgroup of subjects (n = 52) was compared with a comparable group of students who did not participate in the experiment (n = 145) with respect to their performance in a regular multiple choice test. Results show that the acquisition of diagnostic knowledge is mainly fostered by providing erroneous examples in combination with elaborated feedback. These effects were independent from differences in time-on-task and prior knowledge. Furthermore, the effects of the learning environment proved sustainable.