Validity of tests
Validity refers to how well a test measures the characteristic it is intended to measure and whether test performance relates to job performance. A valid test provides meaningful scores that can predict job performance. Validity indicates how useful test scores are for making conclusions about an individual's likely job performance. Reliability ensures test scores are trustworthy but does not guarantee a test is valid for a given purpose. A test's validity is specific to the purpose for which it was designed. Common methods for establishing a test's validity include criterion-related validation by correlating test and job performance, content validation by ensuring the test covers important job tasks, and construct validation by showing the test measures an important job-related trait.
Validity of tests
- 2. Meaning of validity • Validity refers to what characteristic the test measures and how well the test measures that characteristic • Validity tells you if the characteristic being measured by a test is related to job qualifications and requirements • Validity gives meaning to test scores. Validity evidence indicates that there is linkage between test performance and job performance.
- 3. Usefulness of validity …. • It can also tell you what you may conclude or predict about some one from his score on the test. If a test has been demonstrated to be a valid predictor of performance on a specific job, you can conclude that persons scoring high on the test are more likely to perform well on the job than persons who score low on the test, all else being equal.
- 4. Usefulness of validity… • Validly also describes the degree to which you can make specific conclusions or predictions about people based on their test scores. In other words it indicates the usefulness of the test.
- 5. Difference between validity and reliability • Validity will tell you how good a test is for a particular situation; reliability will tell you how trustworthy a score on that test will be. • You cannot draw valid conclusion from a test score unless you are sure that the test is reliable. Even it is reliable it may not be valid. As such you should be careful that any test you select is both reliable and valid for the situation
- 6. Purpose of validity test • A test validity is established in reference to a specific purpose; the test may not be valid for different purposes. For example the test you use to make valid predictions about some one’s technical proficiency on the job may not be valid for predicting his leadership skills or absenteeism rate.
- 7. Methods of conducting of validity studies • There are three methods of conducting validity studies. They are • Criterion related validation • Content related validation • Construct related validation
- 8. Criterion related validation • This requires demonstration of correlation or other statistical relationship between test performance and job performance and job performance. In other words, individuals who score high on the test tend to perform better on the job than those who score low on the test. • If the criterion is obtained at the same time the test is given, it is called concurrent validity; if the criterion is obtained at a later time, it is called predictive validity.
- 9. Content related validation • Content related validation requires a demonstration that the content of the test represents important job related behaviors. In other words, test items should be relevant to and measure directly important requirements and qualifications for the job.
- 10. Construct related validation • This requires a demonstration that the test measures the construct or characteristic it claims to measure, and that this characteristics is important to successful performance on the job. For example construct validity may be used when a bank desires to test its applicants for ‘numerical attitude’
- 11. • The end