reliability

measurement in social science

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July 13, 2026

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In social science, reliability refers to the consistency of a measurement. A reliable test or instrument will produce similar results if administered multiple times under the same conditions. This is distinct from validity, which is the degree to which a test measures what it claims to measure.1

Reliability can be assessed in several ways:
* Scorer reliability: Consistency in scoring by different individuals.
* Content reliability: How well test items sample a specific content area.
* Temporal reliability: Stability of scores over time.

Methods like the comparable-forms technique, test-retest, and internal-consistency measures (e.g., split-half) are used to estimate reliability. A reliability coefficient quantifies this accuracy.12

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