Exploring the relation between <scp>IRT</scp> estimates of within‐person variability in personality and job performance

Abstract The relation between Item Response Theory tree (IRTree) estimates of within‐person variability in responses to Big Five personality items and supervisor ratings of job performance was examined in this research. Using a large incumbent sample ( N = 1108), within‐person variability within and across Big Five domains was estimated using a modern IRTree model. The results suggest that the direction and magnitude of the relation between IRTree estimates of within‐person variability in personality and supervisor ratings of job performance depend on the level at which within‐person variability is estimated (within or across Big Five domains) and the level at which performance is measured (broad or specific dimensions of job performance). Additionally, there were multiple instances in which Big Five within‐person variability estimates predicted job performance over and above trait estimates. The implications of these findings as well as limitations and future directions are discussed.