Intervention and data collection of the study.

The intervention of the study consisted of the differential training of the students in certain content areas: students in group A received training in modules 10, 12 and 15 and no training in modules 11, 13 and 16, and vice versa for students in group B. Training sessions were kept balanced with regard to instructor, length, difficulty and instructional format. Data were collected in the form of ontology development exercises which were distributed evenly over all content areas with two exercises per training module.