The abilities of retarded students: further evidence concerning the stimulus trace factor.

A Wherry-Wherry hierarchical factor solution was obtained on the correlations among 11 WISC-R subtests for a sample of 79 mentally retarded boys and girls. The findings were not only congruent with Vernon's ability paradigm but also suggest that the ability structure for retardates may well be more complex than the structure for normals. The ability hierarchy for the present sample included a general (g) factor defined by positive loadings from all 11 subtests and factors corresponding to the verbal-educational (v:ed) and spatial-perceptual (k:m) parameters. In addition, a stimulus trace (ST) factor corresponding to the ability dimension described by Baumeister and Bartlett was obtained.