RATING ERRORS
HALO EFFECT: The tendency to let someone’s exemplary performance in one dimension influence your rating of the person in other dimensions; assuming that good performance in one dimension means the person is also as competent in other dimensions.
Example: You are filling out the Recommendation of Readiness (ROR) for an employee with whom you have a great relationship. This employee volunteers for unpopular after-school activities, and comes up with creative solutions to problems. Therefore, you have no doubt that the individual is one of your strongest employees in terms of initiative and innovativeness. You don’t know much about the individual’s other abilities. Since you work well with this person you decide to give a recommendation.

LENIENCY EFFECT: The tendency to be somewhat less critical than is appropriate in the evaluation process - i.e., to be too 'easy' and forgiving in assigning ratings.
Example: You are aware that this employee is weak in some dimensions, but you feel that over time and with the right principal as a mentor, this individual has the potential to be a good administrator. Therefore, you recommend the employee even though there are work areas that are in need of improvement.

HARSHNESS ERROR: The tendency to be more critical than is appropriate in the evaluation process; the opposite of leniency effect.
Example: You are meeting with an employee who is ready to assume the job of an administrator. Despite being an above-average employee, this person is far from perfect, so you make a decision not to recommend this individual.

RECENCY ERROR: This occurs when the employee’s job performance at the end of the evaluation period is weighted more heavily in the overall evaluation than is appropriate. Example: You are finding it hard to recall information on an employee’s work performance, other than a project that the individual recently completed that made a big impression on you. This employee has worked at your school for two years. You recommend this individual based on the project completed a couple of weeks ago, and assume it is reflective of the person’s performance throughout the past two years.

CONTRAST EFFECTS: This occurs when a rater lets an extremely strong or weak employee become the standard by which other employees are judged. Example: You just completed a Recommendation of Readiness for one of the best coordinators at your school. When evaluating the next person, who always completes work on time, but without the flair that characterized the work of the exemplary coordinator who you just recommended, you decide not to recommend.

FIRST IMPRESSION ERROR: The tendency of a rater to make an initial favorable or unfavorable judgment about an employee that is not justified by the employee’s subsequent performance. Example: During the first couple weeks of school, a new employee of yours shows great enthusiasm for the job, and makes a lasting positive impression on you. From then on, your judgment of the individual’s job performance is affected by your initial positive impression of the person, leading to inflated ratings of performance.

PRIMING BIAS: The tendency to focus on certain aspects of an employee’s performance (often to the exclusion of other important aspects), due to a cue that has directed attention towards these aspects of performance. As a result of this, a rater may overestimate the performance they have been prompted (or primed) to attend to, and underestimate the presence of other performance factors.
Example: An employee has made mistakes in the past, so you only pay attention to what the employee does wrong but not to what the employee does right, leading to an overestimation of the number of mistakes made and the magnitude of their impact.

STEREOTYPING BIAS: This occurs when a rater assumes something to be true because the individual being rated belongs to a certain group (e.g., male/female). Example: You are evaluating a male employee, who has thus far done a good job in a position that is primarily occupied by females. Although this employee’s performance has been proficient, you do not feel a male can perform as well as a female in a position that requires nurturing skills, so you do not recommend him.

AVAILABILITY BIAS: The tendency to rely on information that is most easily accessed in memory or that is most easily collected or retrieved as “hard” data/documentation. Example: You recommend an employee based on the information in the Candidate Portfolio without considering information from Stull evaluations from previous years or documentation from previous classroom observations.