VALIDITY OF OBSERVER RATINGS OF THE BIG 5 PERSONALITY-FACTORS

The authors examined the validity of observer ratings (supervisor, cow orker, and customer) and self-ratings of personality measures. Results based on a sample of 105 sales representatives supported the 2 hypoth eses tested. First, supervisor, coworker, and customer ratings of the 2 job-relevant personality dimensions-conscientiousness and extraversi on-were valid predictors of performance ratings, and the magnitude of the validities were at least as large as for self-ratings. Second, sup ervisor, coworker, and customer ratings accounted for significant vari ance in the criterion measure beyond self-ratings alone for the releva nt dimensions. Overall, the results suggest that validities of persona lity measures based on self-assessments alone may underestimate the tr ue validity of personality constructs.