Validity & Reliability

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

2. Predictive validity evidence-correlating test scores with a criterion measure collected after a period of time has passed.

3. It is a requirement in order to have a good test and answers the question of "does it measure the instructional objectives."

4. Content Validity

4.1. Seeing if a test question coresponds to what the user decides should be covered in the test.

5. Reliability

5.1. Test-Retest or Stability

5.1.1. Test given twice

5.1.2. Same group of students tested

5.2. Alternate Forms

5.2.1. Giving two alternate forms of a test to the same group and correlating the scores

5.2.2. Prerequisites

5.3. Internal Consistency

5.3.1. Used to yield inflated estimates for speed test

5.3.2. Uses Kuder-Richardson procedure or split half.

6. Interpreting reliability coefficients

6.1. Group validity-affects test reliability

6.2. Scoring reliability-limits test reliability

6.3. Test Length-affects test score reliability

7. Criterion-related validity evideence

8. Item difficulty -afftects test score reliability