Inter-rater reliability assesses what aspect of measurement?

• A. The degree of agreement among different raters
• B. The correlation between items on the same test
• C. The accuracy of predictions relative to external criteria
• D. The stability of measurements over time

Answer: (A)

Inter-rater reliability measures the degree of agreement among different raters. In practice, when more than one clinician or assessor evaluates the same client or rating the same behavior, high inter-rater reliability means their scores line up closely, indicating the scoring is not heavily dependent on who does the rating. This is crucial in social work to ensure consistency and fairness across practitioners and settings. Common ways to quantify it include statistics like Cohen's kappa for categorical ratings or the intraclass correlation coefficient for continuous or ordinal ratings, along with simple percent agreement.

Other concepts refer to different properties: correlation among items on a test speaks to internal consistency, the accuracy of predictions relative to external criteria relates to criterion-related validity, and stability of measurements over time concerns test-retest reliability. Inter-rater reliability specifically focuses on how well different raters agree.