Today’s best managers know that there is a weak relationship between actual employee performance and performance evaluation scores. Managers have tried to improve performance ratings by creating better rating scales, helping raters avoid making evaluation errors (such as rating everyone harshly), training raters to be more accurate, and using 360-degree feedback approaches. Today’s best managers know that the best way to help make performance ratings more accurate is by creating an environment where raters are fair, accurate, and neutral evaluators of employee performance.
Source: Murphy, K. R. 2008. Explaining the weak relationship between job performance and ratings of job performance. Industrial and Organizational Psychology, 1, 148-160