The central role of general ability in prediction.

Three data sets are analyzed that permit double cross-validation of a test battery against criterion variables in a number of educational programs or jobs. The validity of the first general factor score is compared with that obtained from the set of cross-validated regression weights, and is found to account, respectively, for approximately 85, 90 and 120 percent as much criterion variance as the cross-validated regression weights. Small further contributions appear to be made by a mechanical/technical and by a psychomotor factor. However, for a wide range of criterion variables the major role in validity appears to be played by a common general factor.