psychometric reliability

psychometric reliability

The degree to which a psychometric instrument is free from random error, either by testing the homogeneity of content on multi-item tests with internal consistency evaluation or testing the degree to which the instrument yields stable scores over time.

Reliability pertains to questions concerning whether an instrument is accurate, repeatable, sensitive and is distinguished from validation, which answers whether the instrument—e.g., questionnaire—actually measures the selected "construct" (latent variable). For example, a balance (weight scale) is easily understood as a possibly valid instrument for measuring body weight; its reliability would be assessed by measuring the sensitivity, repeatability and accuracy of the balance. The validity of using the balance for a particular purpose could then be established by comparing the measured reliability to the reliability required for that purpose.
References in periodicals archive ?
The research, which will be presented this week at the iDate 2004 inaugural conference in Nice, France, set out to explore and analyze the psychometric reliability and validity of the testing methods used by such services as eHarmony, Match.
Although shorter lengths also were discussed, 14 hours was considered optimal to support the independent assertions of proficiency represented by the test scores, to enable candidates to demonstrate the appropriate depth and breadth of knowledge and skills required to protect the public interest, and to provide adequate psychometric reliability and validity required for such a high-stakes licensing exam.