Reliability

1. Test-Retest or Stability

1.1. Is a method of estimating reliability that is exaclty what the name says

1.2. A test is given twice and the correlation between the first set of scores and the second set of scores is determined

1.3. Only problem with test-retest reliability data is that there is some memory of experience involved the second time the test is taken.

2. Alternate Forms or Equivalence

2.1. Two forms of a test, these forms can be used to obtain an estimate of the reliability of the scores from the test

2.2. Most critical problem is that it takes a great deal of effort to develop one good test

2.3. This method is most often used by test publishers who are creating two forms of their test for other reasons

3. Internal Consistency

3.1. Two Types

3.1.1. Split Halves

3.1.1.1. Involes splitting the test into test into equivalent halves and determining the correlation between them

3.1.2. Kuder-Richardson Methods

3.1.2.1. These methods measure the extent to which items within one form of the test have as much in commonwith one another as do the items in that one form with corresponding items in a equivalent form.