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Performance Management - Avoiding Common Rating Errors
VI. Avoiding Common Rating Errors
To be fair and objective, a Performance Assessment must be based on the employee’s job-related behavior, not on the employee’s personal traits and not a comparison to other employees.
Type of Error - What Not to Do/What to Do
Contrast effect
Don’t evaluate people in comparison with others. "No, he doesn’t really deserve an ‘Outstanding’ rating, but compared to the other employees, he really stands out." Do rate them against the standards for the job.
First impression
Don’t let your initial positive or negative judgment of an employee color your later Performance Assessment. A new supervisor noted one employee who was going through a divorce performing poorly. Within a month, the employee’s performance had returned to its previous high level, but the supervisor’s opinion of the person’s performance was negatively affected by the initial negative impression. Do weigh evidence fairly.
Halo/horns effect
Don’t make inappropriate generalizations from one aspect of an employee’s performance to other areas of that person’s performance. David was outstanding in his ability to repair equipment. His excellence in this area led his supervisor to rate him highly in unrelated areas where his performance was mediocre. Do look at all aspects of your employee’s work.
Similar-to-me effect
Don’t rate people who resemble you more highly that you rate others. Marge, a single mother, had worked hard and been promoted to supervisor. She unconsciously rated several women who were also single parents higher than their performance warranted. Do respect differences in talents among your staff.
Central tendency
Don’t rate employees in the middle of the scale if their performance clearly warrants a significantly higher or lower rating. Bill’s desire to avoid conflict led him to evaluate all employees he supervised as "Satisfactory." Do be honest – it’s only fair!
Negative or positive skew
Opposite of the central tendency. Don’t rate employees higher or lower
than their performance warrants. "No one in my department will get higher than ‘Satisfactory’ because I want them to have something to strive for." Do be honest – it’s only fair!
Recency effect
Don’t allow minor, recent events to have more influence on the rating that those occurring throughout the review period. Because Max doesn’t keep notes of the overall performance or important incidents of his employees’ work, he can’t remember examples from more than two months ago when he sits down to do their performance assessments. Do keep a file for your employee and drop notes into it throughout the year.
Stereotyping
Be careful not to generalize about members of a group and ignore individual differences. Although Joe is the youngest staff member in the unit, he’s one of the most dependable. However, Maria rates the older, more experienced staff higher than Joe because he has fewer years in the job. Do recognize individual differences
Frame of reference error
Be careful not to compare an employee’s performance to your own personal standards. Do rate your employee based on the job description or written performance standards. Peter rates Conrad as "Satisfactory" on attendance. Although Conrad has used his leave time appropriately, Peter feels that only 100% attendance warrants a higher rating.
Information about common rating errors has been adapted from Richard Grote’s The Complete Guide to Performance Appraisal, New York: American Management Association, 1996 and Howard University’s website on its Performance Evaluation Program (www.hr.howard.edu/totcomp/).
Last Updated: August 29, 2007