A modal model of information processing was defined, and nine tasks that could be completed by persons with mental retardation were developed to operationalize the model. Results showed that individual differences in higher mental processes are highly dependent on basic cognitive abilities and can be predicted from them. (Author/JDD)

This article comments on the reporting by Douglas Detterman and others (EC 604 995) of a larger magnitude of g among young adults with mental retardation. Reliance on g-based measures for screening and diagnosis may thus be misleading, by implying that those tested were less differentiated than may be the case. (JDD)

Suggests that individual differences in visual imagery and failure to realize their existence may have affected theories of thought throughout history. Offers possible explanations for the failure to validate thinking style differences in educationally significant ways. Argues that increased understanding of mental imagery can improve teaching.…