5 Types of Bias in a Performance Review

Bias can influence employee performance reviews in incredibly negative ways. A good manager should be objective about the performance of their employees and performance review bias distorts a manager and company’s view of how an employee is performing. In order to maintain an efficient workplace it is imperative that managers avoid any and all bias in employee performance reviews.

1. Recency Bias

The recency bias is one of the trickier forms of bias that may interfere with an effective performance review. When managers are affected by this bias they tend to over or under value short term events to the detriment of the employee’s long term performance. Most performance reviews are set period of times, so failing to take into account the entire performance review time period can lead to ineffective and false performance reviews.

2. The Halo Effect

The halo effect is roughly defined as when a manager values a certain positive quality of an employee to the detriment of objectivity during a performance review. The manager in question may ignore other problems with an employee because he is stellar in one area. However this keeps the employees from knowing about faults in other areas, which keeps them from growing, as well as diminishing their value to the company.

3. Central Tendency Bias

This bias consists of a manager grouping most of his employees into middle level grades while having some extremes in the top and bottom. This bias negatively affects performance reviews by not addressing all of the contributions and problems of employees. This bias should be avoided for efficient growth in the workplace.

4. Spillover Effect Bias

This bias pertains to a manager judging the current performance of an employee by using past performance as a reference point. If a manager is not viewing the performance of an employee clearly due to the spillover effect many problems can arise. This employee’s recent performance reviews will likely not be accurate. The employee and his supervisor will also have an unfairly weighted version of this employee’s performance which will cause other problems in the workplace.

5. Personal Biases

This is among the most common problems with the veracity of employee reviews. Personal biases often prevent an objective analysis of the employee. This bias also goes both ways- people the manager personally likes will benefit and people he personally dislikes will be punished. This is one of the most detrimental forms of review bias for a number of reasons. If an employee believes they are being singled out they may have legal recourse against their employer. This bias also damages the company’s ability to fire and hire effective workers. If personal relationships drive areas like hiring, firing, promotions, transfers and other work related issues the company may not function properly or be profitable. Most companies strive to build teams that are free from personal biases. An effective performance review will do so as well.