The appraisal methods that appear to be in more general use include rating scales, ranking, checklists, forced distribution, paired comparison, essay, critical incidents, and management by objectives. The number of perfomance appraisal methods listed is an indication of the importance placed on the process by the management. Another factor is test validity.
Types of validity
A test is said to be valid for selection purpose if there is a significant relationship between perfomance on the test and performance on the job. The better a test can distinguish between performance on the test and performance on the job, and the better a test can distinguish between satisfactory and unsatisfactory performance of the job, the greater its validity. Applicants’ scores
on valid tests can be used to predict their probable job performance.
The for basic types of validity are
1) Predictive validity
2) Concurrent validity
3) Content validity
4) Construct validity
Each type is discussed as it relates to appraisal
1) Predictive validity: This method of validating employment practices is calculated by giving a test and comparing the results with the job performance of those tested. There are several problems with using predictive validity, even though it is considered sound in a statistical sense. For example, a relatively large number of number of people have to be hired at once, and the test score cannot be considered. Obviously, the firm may intially hire both good and bad employees. Because of these and other problems, another type of validity is often used- concurrent validity.
2) Concurrent validity: Concurrent essentially means ”at the same time”. Using concurrnet validity, current employees (instead of those newly hired) are used to validate the test. The test is given to current employees, and then the scores are correlated with their
performance ratings. A high corelation suggests that the test is able to differentiate between the better and the poorer employees.
3) Content validity: This type of validity uses a logical and less statistical approach. In content validity a person would perform a test which is an actual sample of the work done on the job. thus, an arithmetic test for a cashier would contain some of the calculations that a cashier would have on job. content validity is especially useful if the workforce is not large enough to accommodate better statistical designs.
4) Construct validity: This type of validity is more difficult to deal with than than the others. In practice, construct validity describes some measure (such as a scale or index) of a variable that correlates with measures of other variables. These variables should agree
with a theory as to how they related.