Interpretation of reliability information from test manuals and reviews
Test manuals and independent review of tests provide information on test reliability. The following discussion will help you interpret the reliability information about any test.
The reliability of a test is indicated by the reliability coefficient.
It is denoted by the letter "r," and is expressed as a number ranging between 0 and 1.00, with r = 0 indicating no reliability, and r = 1.00 indicating perfect reliability. Do not expect to find a test with perfect reliability. Generally, you will see the reliability of a test as a decimal, for example, r = .80 or r = .93. The larger the reliability coefficient, the more repeatable or reliable the test scores. Table 1 serves as a general guideline for interpreting test reliability. However, do not select or reject a test solely based on the size of its reliability coefficient. To evaluate a test's reliability, you should consider the type of test, the type of reliability estimate reported, and the context in which the test will be used.
Table 1. General Guidelines for