A performance rating error in which the rater is reluctant to give employees either extremely high or extremely low ratings is referred to as an error of central tendency.
Managers or employee supervisors rate their employees or potential hirers on tendency. This will help with changes that need to be made, to praise an employee for their hard work, or to hirer a new staff member. There are errors that can be made, known as the error of central tendency, if these ratings are not done correct and fair.