The terms positive and negative symptoms have slipped into the language of contemporary psychiatry with comparative ease. It is not uncommon for these expressions to be used with little explanation, both at meeting and in written communications, with the implicit understanding that their meaning is understood and that somehow they are of value to our knowledge of psychopathology. However, that there are no clear guide-lines at present for our use of these terms is shown from a recent survey of psychiatrists' opinions from a market research company (Martin Hamblin Research-Personal Communication). As part of a series of questions asked to many psychiatrists of differing age, geographical location, and status, they were asked about the meaning of these terms, positive and negative symptoms and the proportion of schizophrenic patients having them. Of the categories quoted by Crow (1980–81) as positive symptoms, 68% considered that delusions were positive symptoms, 63% hallucinations, and only 35% thought disorder. In contrast, 18% thought that behaviour disturbance was a positive symptom, a similar figure (15%) being given for passivity feelings. Considerable variation was noted, however, with hallucinations being considered positive by only 33% of London psychiatrists, thought disorder by only 11% of those qualified 16–25 years, and one-quarter of all registrars and psychiatrists from Midland Health Districts considered passivity feelings to fall into this category. Even greater disagreement was recorded for negative symptoms. Thus, the symptom most often associated with this category was apathy, by 52% of respondents. Only 26% considered that withdrawal was a negative symptom, the percentage data for lack of motivation and blunting of affect being 37% and 15% respectively.