There are more ways that we can have a negative impact on evaluations, including our tendency to stereotype. Within organizational behavior, the most typical of these areas are:

Leniency or Stringency
This is a tendency to rate candidates too harshly (so that none of them will ever be able to meet your demanding criteria) or being too easy on them (so that all of them pass with flying colors). Think of how you rate employees who belong to a poorly performing team: do they all rate poorly by association? Also, sometimes we compare employees to ourselves and say things like, “Gee, when I was doing this job I did it a whole lot better than you do.”

Halo/Horn Effect
This tendency has been researched extensively. This is a tendency to rate someone high on all factors (the halo) or low (the horns) because of a global impression you are hanging onto. Likewise, compatibility is the tendency to rate people who are like us higher than their performance indicates. We also tend to rate people who do well in conversation, who are attractive, or well educated, or attended the same school we did, as higher than their performance justifies. Sometimes we also do this when we give a lot of weight to someone’s credentials, even though they may not have done anything for us yet.

Error of Central Tendency
This is our tendency to give average marks to most candidates. Sometimes the rater works on a “no news in good news” basis, and if there have been no complaints filed, they will evaluate accordingly. This also occurs where there are no clearly defined performance standards and we are not certain what would define outstanding performance. Other times, raters are concerned about consequences for giving employees high or low ratings: we sometimes have to explain these ratings to HR or a VP, so we avoid it.