N = 1.

Studies focused on the behavior of only 1 individual are examined. Despite the limitation on generalizing inherent in such studies, selected examples attest their importance in the history of psychology. There frequency in modern psychology is noted, together with their distribution across major topics. The usefulness of an N of 1 in research is viewed as extending beyond the single-case studies of clinician and personologists. An N of 1 is seen as also appropriate when, for the function considered, intersubject variability is low, when opportunities for observing a given class of events are limited, and when a supposed universal relationship is questioned and the obtained evidence is negative. (51 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)