Generalizability Theory as Construct-Related Evidence of the Validity of Job Performance Ratings
Kurt Kraiger, Mark S. Teachout · Human Performance · 1990
Investigations of the construct-related evidence of the validity of performance ratings have been rare, perhaps because researchers are dissuaded by the con- siderable amount of evidence needed to show construct validity (Landy, 1986). It is argued that generalizability (G) theory (Cronbach, Gleser, Nanda, & Rajaratnam, 1972) is well-suited to investigations of construct-related evi- dence of validity because a single generalizability investigation may provide multiple inferences of validity. G theory permits the researcher to partition observed score variance into universe (true) score variance and multiple, distinct estimates of error variance. G theory was illustrated through the anal- ysis of proficiency ratings of 256 Air Force jet engine mechanics. Mechanics were rated on three different rating forms by themselves, peers, and supervi- sors. Interpretation of G study variance components revealed suitable evi- dence of construct validity. Ratings within sources were reliable. Proficiency ratings showed strong convergence over rating forms, though not over rating sources. Raters showed adequate discriminant validity across rating dimen- sions. The expectation of convergence over sources was further questioned.