Job-Specific Applicant Pools and National Norms for Cognitive Ability Tests: Implications for Range Restriction Corrections in Validation Research

Correcting validity coefficients for range restriction requires the applicant pool predictor standard deviation (SD). As this is frequently unknown, some researchers use national norm SDs as estimates of the applicant pool SD. To test the proposition that job-specific applicant pools are markedly more homogeneous than broad samples of applicants for many jobs, job-specific applicant pool SDs on the Wonderlic Personnel Test for 80 jobs were compared with a large multijob applicant sample. For jobs at other than the lowest level of complexity, job-specific applicant pool SDs average 10% lower than the broad norm group SDs. Ninety percent of the job-specific applicant pool SDs lie within 20% of the norm group SD, suggesting that reducing a norm group SD by 20% provides a conservative estimate of the applicant pool SD for use in range restriction corrections for other than low-complexity jobs.