Error of central tendency refers to the phenomenon where raters assign scores to most subjects that are average regardless of the differences in performance between subjects. A rater can be someone who is judging a performance or skill. An example would be a job interviewer or a manager rating an employee’s job performance.
Central tendency is a term used to refer to an average or the middle range of a distribution. Rater errors occur because when evaluating another person our unique biases and perceptions influence how we rate another person. These errors often go unnoticed so the person continues to make errors without realizing they are being influenced by their personal perceptions.