Evidence for the validity of dimensions in the presence of rater source factors.

Empirical research on the structure of 360-degree feedback ratings indicates that the source of the ratings (e.g., superiors, peers, subordinates) explains more variance than do the performance dimensions or competencies being measured. One alarming implication of this finding from studies of the internal validity of 360 ratings is that there appears to be little evidence to support the common practice of interpreting 360s in terms of dimension scores. To address whether rater-source factors are so pronounced that they should preclude the use of dimension scores, we considered the question from an external validity perspective and developed and tested a personality-based nomological network around both dimension and rater-source factors in a 360 data set. Using a sample of 825 managers and their feedback providers (3,300 participants overall), we found that ratee personality correlated more strongly with dimension scores than with source factors. This provides evidence to support the common practice of interpreting 360-degree feedback in terms of scores for separate dimensions and competencies, despite most of the variance in observed ratings being due to rater-source factors rather than dimensions.