Reliability & Validity

1. If research is valid then it is answering the question that supposed to answer.

1.1. If research is reliable then the tools you are using for measurement in your research are accurate.

2. Test–Retest or Stability Test–retest is a method of estimating reliability , this is when a test is given twice and the correlation between the first set of test scores and the second set of scores is determined.

2.1. Alternate Forms or Equivalence If there are two like forms of a test, these forms can be used to obtain an estimate of the reliability of the scores from the test.

2.2. Internal Consistency If the test in is intende to measure a single basic concept, it is reasonable to assume that people who get one item right will be more likely to get other, similar items right.

2.2.1. To find the split-half reliability, each item isassigned to one half or the other. Then, the total score for each student on each half is determined and the correlation between the two total scores for both halves is computed.

2.2.1.1. These methods measures to what extent in which items within one form of the test have as much in common with one another so that the items in each form is coresponing.

3. THE RELIABILITY of a test refers to the consistency with which it yields the same rank for individuals who take the test more than once.

4. Why is Validity and Reliability Important?

5. Making Sure Tests Measure What Is Intended to Measure

5.1. Content Validity

5.2. *is established by inspecting test questions to see whether they correspond to what the user decides should be covered by the test

5.3. - content validity provides evidence pertaining to whether the test looks valid, but not whether the reading level of the test is too high or if the items are poorly constructed.

6. Criterion-Related Validity Evidence

6.1. *Concurrent criterion-related validity evidence- are measures that can be administered at the same time as the measure to be validated.

6.2. Predictive validity evidence refers to how well the test predicts some future behavior of the examinees. This form of validity evidence is particularly useful and important for aptitude tests, which attempt to predict how well test takers will do in some future setting.

6.3. A test has construct validity evidence if its relationship to other information corresponds well with some theory.