As humans, we are subject to a range of cognitive biases. One strong bias is the “Availability Heuristic”, the tendency to let a single, large, or recent action dominate our perception. Whenever you assess performance and are in a position to supply feedback to fellow employees, fight against this bias to ensure your assessment is fair.
Short Term
When an employee exceeds expectations, recognize their achievement promptly. Timely feedback is the best feedback. If the effort deserves a reward, consider a merit award, spot bonus, or whatever your organization uses to acknowledge a job well done. But don’t mistake a single instance of good effort for sustained high performance. Only in special situations should you consider longer-term rewards, such as promotions and raises, for individual acts.
Likewise, when an employee disappoints, address their shortcomings quickly. Often it will be a small issue, one that you can readily talk through to ensure that corrective action occurs. Sometimes it will be a larger issue, one that calls for a remedial plan. Very rarely, an employee will commit a major breach of ethics, law, or safety—in which case, you must take more drastic action immediately.
Long Term
Individual incidents, both good and bad, should be a part of your longer-term feedback. They can be used to illustrate important behaviors. But don’t focus exclusively on these data points; rather, look for a sustained pattern of accomplishment. A consistent performance over the longer term is almost always more important than isolated incidents.
Promotions and raises, or the lack of either, should reflect a well-considered evaluation of overall achievement. People have a good grasp of fairness and can recognize when these important rewards are unjustly distributed. If you fall victim to the Availability Heuristic, you will over or under reward the people relying on you for a fair accounting.
The Pattern
Because the overall pattern can be difficult to discern in retrospect, keep notes on all the folks you are expected to assess, detailing both positive and negative aspects of their performance. Talk regularly with anyone you are expected to evaluate, probably in a 1:1 meeting. This is an ideal time for updating your notes.
Record major items, but also note more routine accomplishments or failures. Are deadlines regularly made or missed? Did the person go out of their way to help someone? Did the quality of their work stand out in some way? In what ways is this person a positive or negative influence? These notes will be a useful reminder of many smaller issues.
To properly assess performance, avoid biases that tempt you to focus on isolated instances, and, instead, consider the pattern.