Performance appraisal plays an important role in many organizations, and how to improve its effectiveness is the major concern in the recent 50 years. Information is very useful in evaluating the performance of organizations or individuals while it is not noticed sufficiently in the literature. In this paper, information has been identified as a determinant of accurate performance appraisal. Comprehensive information enables accurate appraisal and the one who has information should be included and valued in the appraisal process. Customers, both internal and external, due to their enough information and powerful motivation, can enjoy a great consideration in the performance appraisal process.