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Polytomous Reliability Analysis

Polytomous reliability analysis estimates the internal consistency or precision of measurement for scales composed of items with more than two ordered response categories, such as Likert-type, rating, or partial-credit items. It corrects a well-known underestimation bias in conventional Cronbach's alpha by working with polychoric correlations or IRT-based precision indices.

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Sources

  1. Green, S. B. & Yang, Y. (2009). Reliability of summed item scores using structural equation modeling: An alternative to coefficient alpha. Psychometrika, 74(1), 155–167. DOI: 10.1007/s11336-008-9099-3
  2. Zumbo, B. D., Gadermann, A. M. & Zeisser, C. (2007). Ordinal versions of coefficients alpha and theta for Likert rating scales. Journal of Modern Applied Statistical Methods, 6(1), 21–29. DOI: 10.22237/jmasm/1177992180

Related methods

ScholarGatePolytomous Reliability Analysis (Reliability Analysis for Polytomous Items). Retrieved 2026-06-04 from https://scholargate.app/en/psychometrics/polytomous-reliability-analysis