Fostering diagnostic knowledge through computer-supported, case-based worked examples: effects of erroneous examples and feedback.

Objectives: A case-based, worked example approach was realised in a computer-based learning environment with the intention of facilitating medical students' diagnostic knowledge. In order to enhance the effectiveness of the approach, two additional measures were implemented: erroneous examples and elaborated feedback. In the context of an experimental study, the two measures were varied experimentally.

Methods: A total of 153 medical students were randomly assigned to four experimental conditions of a 2 x 2-factor design (errors versus no errors, elaborated feedback versus knowledge of correct result [KCR]). In order to verify the sustainability of the effects, a subgroup of subjects (n = 52) was compared with a control group of students who did not participate in the experiment (n = 145) on a regular multiple-choice question (MCQ) test.

Results: Results show that the acquisition of diagnostic knowledge is mainly supported 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.

Conclusions: Our results demonstrate that the case-based, worked example approach is effective and efficient.