Types of validity and reliability
by Elizabeth McMillin
1. Validity
1.1. Content validity evidence
1.2. Criterion- related validity evidence
1.2.1. Validity refers to the accuracy of an assessment -- whether or not it measures what it is supposed to measure. Even if a test is reliable, it may not provide a valid measure. Tests should be reliable and it should not matter when a student takes a test, what time of day or what day of the week.
1.3. Construct validity evidence
2. Reliability
2.1. Test-retest
2.2. Alternative form
2.2.1. Reliability refers to the extent to which assessments are consistent. Even if a test is reliable, it may not provide a valid measure. Test should be accurate at what they measure all the time.