Types of Reliability

1. Internal Consistency

1.1. Items in a test must correlate/relate to each other

2. Split-Half Methods

2.1. This is when you split a test in two equal halfs and then administer the test. (Related to Internal Consistency)

2.1.1. Odd-Even Reliability

2.1.1.1. The process of splinting the test into half with one half of the test with even numbers and the second half with odd numbers.

3. Kuder-Richardson Method

3.1. Also known as the Coefficient Alpha. This is another method of estimating internal consistency.

3.1.1. KR20 complicated formula but accurate. Used by professional test makers.

3.1.2. KR21 easy formula but less accurate. (used most often)

4. Test-Retest (Stability)

4.1. estimating reliability of the same test on the same students at different times.

5. Alternate Form (Equivalence)

5.1. Also known as Parallel Form. This is two equivalent forms of a test. Usually used for test security.