A model of language abilities in matrix form is described in which areas of language ability are defined in terms of the effects of receptive and expressive language processes on four linguistic levels: phonology, morphology, syntax, and semantics. (Author)

This article considers the models and beliefs of language clinicians, as reflected by their choice of specific assessment instruments or measurement methods. Differences in construct and philosophy are demonstrated in a review of personality and vocational preference inventories and several subtests of sentence production. (DB)