Cognitive ability and job experience as predictors of work performance

The relative importance of cognitive ability and job experience in the prediction of work performance was assessed in a sample of 176 manufacturing workers. The issue of whether the validity of cognitive ability changes as job experience increases was also explored. Job incumbents completed the Bennett Mechanical Comprehension Test (The Psychological Corporation, 1980) and the Numerical Ability subscale of the Employee Aptitude Survey (F. Ruch & W. W. Ruch, 1983). Work performance was rated by supervisors on 3 dimensions. Results indicated that both ability and experience were important predictors of work performance. Furthermore, the validity of the Employee Aptitude Survey increased as job experience increased. This finding is consistent with the divergence hypothesis outlined by F. L. Schmidt, J. E. Hunter, A. N. Outerbridge, and S. Goff (1988). Validities for the Bennett test did not increase with levels of experience, supporting a noninteractive hypothesis. It is concluded that certain ability measures may actually measure job knowledge.