A cluster analytic study was conducted to derive behaviorally homogeneous subtypes of pervasive developmental disorders (PDD) based on a range of behavioral symptoms that characterize autism. Analysis of data on 34 children with PDD, 27 of whom met criteria for autism, indicated 4 distinct groups differing on independent measures of social,…

This paper examines several recent lines of research concerning category clustering and describes an alternative to the standard category clustering procedure used to study recall organization in younger children. The specific issue considered is the age at which children first show evidence of spontaneous category clustering in their free-recall.…