ABSTRACT
This chapter emphasizes performance ratings and focuses on ratings as assessment methods, not on their use in performance management. In rating a product, the time from observation to evaluation is a few minutes; for annual job performance ratings, it might be a full year. Graphic rating scales are the most common of all rating methods. They can be used for overall ratings, but they are used more often to rate different aspects or dimensions of overall performance. Behavioral description seems reasonable to assume that raters can offer better assessments if they avoid glittering generalities or ambiguities and describe specific on the job behavior or outcomes. Measurement implies individual differences in the trait measured, and they imply variance and the evaluation of possible sources of variance in the resulting measures. Competent evidence of psychometric validity is rarely sought; in fact, most often, no psychometric evaluation occurs at all beyond possible checks on interrater agreement or reliability.
