What do we know about job knowledge tests? A 30-year update of validity evidence

Job knowledge tests (JKTs) are widely used for selection and promotion, as well as for certification in professions such as law, medicine, and education. Yet evidence regarding the criterion-related validity of JKTs is based primarily on a brief meta-analysis published more than 30 years ago (Dye et al., 1993). The present study provides an updated meta-analysis of JKT validity data. Analyses based on 122 studies revealed mean operational validity estimates of .28 for job performance (k = 84, N = 25,468, SD_r = .12), .36 for training performance (k = 39, N = 123,845, SD_r = .00), and -.06 for turnover (k = 12, N = 18,349, SD_r = .03). Importantly, operational validities for job performance were larger for job-specific JKTs (.34) than for nonjob-specific tests (.19) and when the criteria included job knowledge (.41) than when they did not (.22). In addition, JKTs administered to job applicants (.32) or current employees (.29) in organizational settings were associated with higher validity than tests administered to people seeking certification in their chosen field (.20). Finally, we tested the mediating role of job knowledge between other antecedents and job performance. Job knowledge statistically fully mediated the relationship between cognitive ability and job performance, partially mediated the relationship between job experience and performance, and did not mediate the relationship between conscientiousness and performance. Overall, these results provide a contemporary synthesis of validity evidence for JKTs in various situations, as well as the role job knowledge plays in other predictors of job performance. (PsycInfo Database Record (c) 2026 APA, all rights reserved).