Examine why organisations need to assess the performance of their employees and identify how the appraisal process affects the individual at work. The results or feedback gathered from this assessment are an effective way of identifying training needs and also a source to determine the employee's qualities and performance. Rewards or compensation methods can also be derived from this exercise. However, the results' validity, reliability and consistency have always been the main concerns.
Reliability is concerned about the stability of a measure over time of different raters.
Consistency is the regularity of measure as compared with the rates evaluated at different time periods. Halo effect, which is the tendency of an appraiser to rate an appraisee the same on all performance dimensions because of a general impression. Similarity effect which is the tendency of an appraiser to rate an appraisee based on the appraiser's expectation. Leniency effect which is the tendency of an appraiser to rate an appraisee on an average rating. Central tendency which refers to an appraiser who rates an appraisee on a uniform or standard rating.