Diagnosis: Description or Prescription? A Case Study in the Psychology of Diagnosis

This paper deals with the epistemology of diagnosis. It is suggested that the conventional view of diagnosis, which sees the diagnostician as one who describes and/or explains pathological phenomena, is inadequate. A contrasting model is proposed, one that conceptualizes diagnosis as a prescriptive and problem-solving activity. The difference between these two models is explored with particular reference to the problem of defining “illness.” The relevance of diagnosis to perception and cognition is also discussed.