The traits assessed on these scales include employee attributes such as cooperation, communications ability, initiative, punctuality and technical (work skills) competence. The nature and scope of the traits selected for inclusion is limited only by the imagination of the scale's designer, or by the organization's need to know.
The one major
provision in selecting traits is that they should be in some way relevant
to the appraisee's job. The traits selected by some organizations have
been unwise and have resulted in legal action on the grounds of discrimination.
Each employee is subjected to the same basic appraisal process and rating criteria, with the same range of responses. This encourages equality in treatment for all appraisees and imposes standard measures of performance across all parts of the organization.
methods are easy to use and understand. The concept of the rating scale
makes obvious sense; both appraisers and appraisees have an intuitive appreciation
for the simple and efficient logic of the bipolar scale. The result is
widespread acceptance and popularity for this approach.
For example, the trait "initiative" might not be very important in a job that is tightly defined and rigidly structured. In such cases, a low appraisal rating for initiative may not mean that an employee lacks initiative. Rather, it may reflect that fact that an employee has few opportunities to use and display that particular trait. The relevance of rating scales is therefore said to be context-sensitive. Job and workplace circumstances must be taken into account.
This is an assumption very difficult to prove in practice. It is possible that an employee's performance may depend on factors that have not been included in the selected traits. Such employees may end up with ratings that do not truly or fairly reflect their effort or value to the organization. Employees in this class are systemically disadvantaged by the rating scale method.
Selective perception is the human tendency to make private and highly subjective assessments of what a person is "really like", and then seek evidence to support that view (while ignoring or downplaying evidence that might contradict it).
This is a common and normal psychological phenomenon. All human beings are affected by it. In other words, we see in others what we want to see in them.
An example is the supervisor who believes that an employee is inherently good (halo effect) and so ignores evidence that might suggest otherwise. Instead of correcting the slackening employee, the supervisor covers for them and may even offer excuses for their declining performance.
On the other hand, a supervisor may have formed the impression that an employee is bad (horns effect). The supervisor becomes unreasonably harsh in their assessment of the employee, and always ready to criticize and undermine them.
The horns and halo effect is rarely seen in its extreme and obvious forms. But in its more subtle manifestations, it can be a significant threat to the effectiveness and credibility of performance appraisal.
For example, to one appraiser, an employee may demonstrate the trait of initiative by reporting work problems to a supervisor. To another appraiser, this might suggest an excessive dependence on supervisory assistance - and thus a lack of initiative.
As well, the language and terms used to construct a scale - such as "Performance exceeds expectations" or "Below average skill" - may mean different things to different appraisers.
The most common rating error is central tendency. Busy appraisers, or those wary of confrontations and repercussions, may be tempted to dole out too many passive, middle-of-the-road ratings (e.g., "satisfactory" or "adequate"), regardless of the actual performance of a subordinate. Thus the spread of ratings tends to clump excessively around the middle of the scale.
is worsened in organizations where the appraisal process does not enjoy
strong management support, or where the appraisers do not feel confident
with the task of appraisal.