Question

.What are three ways to assess reliability? Specifically, name and describe three ways of administering a test that would allow a psychologist/educator to assess reliability

Answer 1

The reliability of a test refers to stability of measurement over time. When a person's data entry skills are measured on two occasions (with no special training in between), the two sets of scores should be similar. Reliability is often measured with a reliability coefficient, which is simply a correlation between sets of scores from people who have been given the test on two occasions (X = first time score on the test, Y = second time score on the test) - see the correlation module for review.

There are three (3) ways to measure the reliability of a test or inventory: Test-retest, Split-half, and Alternate forms.

1.

Test-retest - the same test is given to the same people on two occasions. The scores are correlated, and if the reliability coefficient is positive and high, the test is reliable.

2.Split-half - after being taken by a sample, the answers to the test are divided into two halves (e.g., the odd-numbered versus the even-numbered items). Scores on each half are correlated. If the test is reliable, the scores on the two halves should show a high positive reliability coefficient (correlation

3.

Alternate forms - two versions of the test are constructed, and given to the same people on two occasions. Scores on the two forms should show a high positive reliabiilty coefficient (correlation).