The appraiser may be any person who observes the employee while performing a job. The appraiser has thorough knowledge about the job content, contents to be appraised, and standards of contents. The appraiser should prepare reports and make judgments without bias. Typical appraisers are supervisors, peers, subordinates, employees themselves, users of service, and consultants.

Supervisors include superiors of the employee, other superiors having knowledge about the work of the employee, and department heads or managers. General practice is that immediate superiors appraise the performance, which in turn is reviewed by the departmental head manager. This is because supervisors are responsible for managing their subordinates and they have the opportunity to observe, direct and control the subordinate continuously. Moreover, they are accountable for the successful performance of their subordinates. On the negative side, immediate supervisors, may emphasis certain aspects of employee performance to the neglect of others. Also, managers have been known to manipulate evaluations to justify their decisions on pay increases and promotions.

Peer appraisal may be reliable if the work group is stable over a reasonably long period of time and performs tasks that require interaction. However, little research has been conducted to determine how peers establish standards for evaluating others or the overall effect of peer appraisal on the group