The knowledge encapsulation theory (H. Schmidt and H. Boshuizen, 1992) predicts that experts under certain conditions shift from the use of clinical knowledge to elaborated biomedical knowledge. In normal routine cases, experts process cases with their encapsulated clinical knowledge. These differences in processing are reflected in clinical case recall. However, the specific conditions under which this takes place have never been isolated in a controlled setting. The experimental manipulations used in this study were case format and elaborative instruction. Participants were 30 experts (nephrologists in hospitals in the Netherlands), 24 intermediates (students who had completed an internship in internal medicine), and 24 novices (fourth year medical students). Only elaborative instruction in combination with laboratory data cases resulted in a significant increase of recall and a decrease in recall of encapsulated concepts of the experts. These results indicate a processing shift to a lower level biomedical knowledge. (Contains 4 figures and 18 references.) (Author/SLD)