Various Types of Validity and Reliability

1. Content validity evidence- is assessed by systematically comparing a test item with instructional objectives to see if they match. content validity evidence does not yeld a numerical estimate of validity.

2. A valid test measures what it is supposed to measure.

3. Criterion-related validity evidence- is established by correlating test scores with an external standard or criterion to obtain numerical estimate of validity evidence.

4. Concurrent validity evidence is determined by correlating test scores with a criterion measure collected at the same time.

5. Redictive validity evidence is determined by correlating test scores with a criterion measure collected after a period of time has passed.

6. Reliability refers to the stability of a test score over repeated administrations.

7. A reliability test will yeld stable scores over reapeated administrations, assuming the trait being measured has not changed.

8. Test-retest estimates of reliability are obtained by administering the same test twice to the same group of individuals, with a small time interval between testing, and correlating the scores. the longer the time interval, the lower test-retest estimates will be.

9. Internal consistency reliability assesses the consistency of results across items within a test.