The roles of general cognitive ability (g) and specific abilities or knowledge (s) were investigated as predictors of work sample job performance criteria in 7 jobs for U.S. Air Force enlistees. Both gand s (the interaction of general ability and experience) were defined by scores on the first and subsequent principal components of the enlistment selection and classification test (the Armed Services Vocational Aptitude Battery). Multiple regression analyses, when corrected for range restriction, revealed that g was the best predictor of all criteria and that i added a statistically significant but practically small amount to predictive efficiency. These results are consistent with those of previous studies, most notably Army Project A (

The roles of general ability (g) and specific abilities (s1…sg) were investigated in prediction of job‐training‐school grades. Subjects were 78,041 Air Force enlistees in 82 jobs. General ability and specific abilities were defined by scores on the first and subsequent unrotated principal components of the enlistment selection and classification test, the Armed Services Vocational Aptitude Battery. Linear models analyses revealed that s1…s9 added little to the prediction afforded by g. It was also determined that a common prediction equation for all jobs was almost as predictive as an equation for each job.

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K. Pearson (1903) recognized that the correlation coefficient was subject to distortion when a sample was censored or preselected in some way. He proposed 3 univariate correction formulas for better estimates in these circumstances. These have become well known from the work of R. L. Thorndike (1949). D. N. Lawley (1943) proposed a general solution usually called the multivariate correction for range restriction. Both Pearson's and Lawley's corrections are discussed and examples are presented. Of particular interest are the opportunities for the corrected correlations to change sign as a result of the correction. Numerical examples are presented that show that correlations can change signs in the Pearson-Thorndike Case 3 and in Lawley's general solution. Pearson (1903) observed that the correlation coefficient computed in a sample censored in such a way as to reduce variance in one or both of the variables would underestimate the population value. Such censoring that results in a reduction in variance has become known as range restriction. Sometimes the restrictions are so severe that the correlation in the censored sample does not have the same sign as the population correlation. Pearson and Lawley (1943) have provided procedures for correcting these correlations, not all of which allow the sign to change.There is so little published experience in the application of correction procedures that it is not surprising that journal reviewers and members of national oversight committees question results when signs of correlations change as a consequence of application of the procedures. A review of Educational and Psychological Measurement, Journal of Applied Psychology, and Personnel Psychology for the years 1988 through 1992 showed that only 4% of the validity articles were corrected for range restriction. Commonly used statistical packages do not provide procedures to compute either univariate or multivariate corrections. This has contributed to ignorance about correction procedures (Atwater, 1992;Seymour, 1988;Sternberg & Wagner, 1993). Although most researchers have some familiarity with the corrections, knowledge about sign changes is largely absent. This lack of knowledge is the motivation behind the present article.Rectification is past due. An example of a correlation chang-

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