Moving beyond Cronbach’s Alpha and Inter-Rater Reliability: A Primer on Generalizability Theory for Pharmacy Education

  • Michael Peeters University of Toledo


Background: When available, empirical evidence should help guide decision-making. Following each administration of a learning assessment, data becomes available for analysis. For learning assessments, Kane’s Framework for Validation can helpfully categorize evidence by inference (i.e., scoring, generalization, extrapolation, implications). Especially for test-scores used within a high-stakes setting, generalization evidence is critical. While reporting Cronbach’s alpha, inter-rater reliability, and other reliability coefficients for a single measurement error are somewhat common in pharmacy education, dealing with multiple concurrent sources of measurement error within complex learning assessments is not. Performance-based assessments (e.g., OSCEs) that use raters, are inherently complex learning assessments.

Primer: Generalizability Theory (G-Theory) can account for multiple sources of measurement error. G-Theory is a powerful tool that can provide a composite reliability (i.e., generalization evidence) for more complex learning assessments, including performance-based assessments. It can also help educators explore ways to make a learning assessment more rigorous if needed, as well as suggest ways to better allocate resources (e.g., staffing, space, fiscal). A brief review of G-Theory is discussed herein focused on pharmacy education.

Moving Forward: G-Theory has been common and useful in medical education, though has been used rarely in pharmacy education. Given the similarities in assessment methods among health-professions, G-Theory should prove helpful in pharmacy education as well. Within this Journal and accompanying this Idea Paper, there are multiple reports that demonstrate use of G-Theory in pharmacy education.


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Received 2019-07-12
Accepted 2020-07-19
Published 2021-02-26