An evaluation of exemplar-based models of generalization was provided for illdefined categories in a category abstraction paradigm. Subjects initially classified 35 high-level distortions into three categories, defined by 5, 10, and 20 different patterns, followed by a transfer test administered immediately and after 1 wk. The transfer patterns included old, new, prototype, and unrelated exemplars, of which the new patterns were at one of five levels of similarity to a particular training (old) stimulus. In both experiments, increases in category size and oldnew similarity facilitated transfer performance. However, the effectiveness of old-new similarity was strongly attenuated by increases in category size and delay of the transfer test. It was concluded that examplar-based generalization may be effective only under conditions of minimal category experience and immediacy of test; with continued category experience, performance on the prototype determines classification accuracy.

A group of 211 first-to fourth-grade children who had experienced one or more recent stressful life events were compared to a demographically matched sample of 211 children who had not experienced such events on measures of school adjustment problems and competencies. Stressful life events were found to be associated with the presence of more serious school adjustment problems and fewer competencies. Those associations were strongest for children who had experienced multiple recent stressful events. The importance of preventive interventions for this at-risk group was emphasized and future research steps in the area were considered.

Teacher-rated adjustment differences among young elementary school children from (a) a recent sample and a 1974 cohort, and (b) urban/suburban, male/female, and grade-level subgroups were examined. A problem behavior checklist (Classroom Adjustment Rating Scale) and a school competence measure (Health Resources Inventory) for 974 children from 5 urban and 5 suburban schools were completed by 101 first- to fourth-grade teachers. Children from the more current cohort were rated as significantly more maladjusted than those from the earlier sample on 8 of 10 adjustment variables. In the recent sample, girls and suburban children evidenced a greater number of school competencies and fewer problem behaviors than boys and urban children, respectively. The implications of these findings for the future use of the teacher rating scales are discussed.

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