Thirty-six retarded and 36 nonretarded children and adolescents, individually matched for mental age, were given discrimination problems at two levels of stimulus complexity to test the hypothesis that retarded persons require more trials to reach criterion on the more complex problems. (Author)

These results provide a more precise attentional interpretation of both preference and pretraining effects. (Authors)

There should be a meaningful discussion on the importance of awareness of group sensitivities if children are to be worked with effectively. It is obvious that social consciousness is changing radically in these volatile times. This article reviews some of the significant changes. (Author/NH)

Results indicate that dimensional shifting represents some form of nonverbally mediated learning rather than a more limited form of discrimination learning bound to the specific sensory modality of training. (MH)