The factorial structure of the ITPA and WISC subtests in three diagnostic groups.

An image analysis of the ITPA and WISC Subtest Scores of three diagnostic groups was done. In two of the diagnostic groups, a regular classroom group and an LLD group, a general linguistic factor, a visual-motor factor, and a mediation factor appeared to emerge. A general ITPA factor, a general WISC factor, and an expressive factor were extracted from the mentally retarted group's data. Differences among the factors of diagnostic groups were observed and commented upon after a canonical correlation of factor loading matrices.