 There are various ways in which diagnosis is taught and operationalized in clinical settings: in some subspecialties in particular, “pattern” recognition often using pictorial representations seems to be common, and hence diagnosis is a form of recognizing repeated patterns. However this approach can be dangerous particularly among novices, given the large number of similar patterns among common diseases. Some have claimed that the making of a diagnosis is both a deontic act and computable, and that diagnoses are relative only inasmuch as they occur in a complex context which in turn makes them a social practice (Sadegh-Zadeh 2011). Computer-assisted diagnostic techniques have improved and are used increasingly in clinical settings; Kenneth Schaffner (1981) provided an early analysis of the criteria which an ideal diagnostic logic would need to satisfy (for updated discussions see Schaffner 1993, 2010, and for arguments about the limitations of such types of diagnosis see Wartofsky 1986). In recent years there is a relative consensus among medical professionals and those involved in medical informatics that medical diagnosis almost certainly relies on some form of “fuzzy logic” (e.g., Sadegh-Zadeh 2000; Barro and Marin 2002).