Illustrated multiple choice examinations.

Interpretation of visual data is an essential component of clinical competence. Illustrated multiple choice items have been used to measure interpretation, but the effects of introducing visual material into multiple choice items has not been critically assessed. A series of problem-sequenced multiple choice items containing, in the stem, a description of visual data such as a radiologist's report, was selected and matched with identical items where the description was replaced by reproductions of the original data. These two series of items were arranged into two parallel examinations which were taken by groups of final year medical students. From a comparison of the performance of the students in these two examinations it is concluded that substitution of actual visual data for the written description increases the difficulty of items, but is without consistent effect on discrimination. The illustrated format was commended by students for its clinical relevance but certain problems with the reproduction of radiographs and the selection of data have been revealed.