A longitudinal study of 120 children through grades one to six was undertaken. The present study focused on the intermediate grades (four through six). The goals were to explore the relationships among perceptual processing ability development, articulatory accuracy, intelligence, and academic achievement. The assessment battery consisted of an original five-part perceptual test battery; the Bender Visuo-Motor Gestalt test, the Dual Modality Test of Articulation, and the Metropolitan Achievement Test. The major findings of the study were that: the perceptual tests showed a yearly change characteristic of developmental processes; perceptual process ability and articulation errors became asymptotic by the end of the third grade; there was no discernible difference in articulation accuracy whether or not a child was exposed to speech therapy during the first three grades; there was a continuing effect upon school achievement of the level of perceptual processing ability at grade one; there was almost no discernible relationship between early articulation ability and school achievement at any grade level; and speech therapy did not enhance school achievement of those children who were exposed to it over those who were not. (Author)