summarise: The most common rating errors that are associated with PAs are: Personal bias: Involving preferential and nepotistic practices, personal bias is the most common rating error and derives from bias either in favour of or against an employee. It is not performance related, may be committed consciously or unconsciously, and is related to factors such as race, class, religion, gender, age, disability and level of self-confidence, or to institutional characteristics such as seniority. When it occurs in the workplace, subordinates whom the appraiser likes are ranked highly and those he or she dislikes obtain lower ratings. Personal bias in a work setting creates discrimination of various forms and diminishes the appraiser's accuracy. Stereotyping: Appraiser error may arise when an employee is generalised as belonging to an affinity group or identified as possessing the same presumed characteristics as the group. Different types of stereo- types exist, for example, race, class, ethnicity, gender and age stereo types . An example of a gender stereotype is perceiving pregnant women as sluggish regardless of what differentiates them from other employees. Obviously, a stereotypic generalisation like this may influence the PAs of pregnant women negatively, regardless of how they have performed over the period in