General and Specific Abilities as Predictors of School Achievement

Abstract
The purpose of this study is to investigate the relations between aptitude variables and school achievement using a model of ability which allows simultaneous identification of general and specific abilities. A battery of 16 aptitude tests was administered in the 6th grade and course grades were collected in 17 different subject matter areas in the 9th grade (N = 866). For the aptitude tests a confirmatory factor model is fitted with a general factor (G) along with nine orthogonal, residual factors. Some of the residual factors are quite broad (Crystallized intelligence, Gc1, and General visualization G1), but most are narrow factors identified by pairs of tests (e.g., V1, Ms1, Num Ach1, Vz1, S, and Cs1). A model is fitted to the 17 course grades as well. The model includes a general school achievement factor (GENACH) and domain specific achievement factors in areas such as science-mathematics (SCIENCE), social science (SOCSCI1), language (LANG1) and spatial-practical performance (SPATPR1). Relating the l...