Since all tests have some error, reliability coefficients never reach 1.0. A coefficient of 0 means no reliability and 1.0 means perfect reliability. A test produces an estimate of a student’s true score, or the score the student would receive if given a perfect test however, due to imperfect design, tests can rarely, if ever, wholly capture that score. The values for reliability coefficients range from 0 to 1.0. Reliability is important in the design of assessments because no assessment is truly perfect. This guide explains the meaning of several terms associated with the concept of test reliability: “true score,” “error of measurement,” “alternate-forms reliability,” “interrater reliability,” “internal consistency,” “reliability coefficient,” “standard error of measurement,” “classification consistency,” and “classification accuracy.” It also explains the relationship between the number of questions, problems, or tasks in the test and the reliability of the scores. The following table outlines three common reliability measures. WEIBULL++:- Reliability Life Data Analysis 2. The reliability of test scores is the extent to which they are consistent across different occasions of testing, different editions of the test, or different raters scoring the test taker’s responses. Some of the Reliability testing tools used for Software Reliability are: 1. Test-retest reliability is measured by giving the same test to the same test respondents on two separate occasions. Test Reliability-Basic Concepts Author(s):ĭocument Type: Report Page Count: 46 Subject/Key Words:

Reliability of test scores