The Use of Critical Cues and Prior Probability in Decision-Making

Abstract

Six case vignettes were administered to 76 subjects, comprising 62 students and 14 expert physicians. The aim was to show how the different groups used.prior probability and strong individual cues, as opposed to patterns, in coming to a diagnosis. Diagnostic confidence was also assessed to see how this varied with expertise.It was tentatively concluded that the novice is more likely to perceive in patterns than the expert, the latter being more adept at handling prior probability as a separate cue. Experts are also better at perceiving individual, heavily weighted cues than novices and are more likely to accept incomplete patterns to make a diagnosis.In spite of less knowledge, students will make a positive diagnosis more often than experts. This may be a reflection on educational methods, where it is threatening not to know and where students do not learn that diagnosis is probabilistic and uncertain.These are indications to teach better concepts of prior probability, weighting of cues and the uncertain nature of diagnosis, as well as being less threatening if students do not <know>.