2006/11/06 by James M. Graham · 3 citations
Decision Sciences · Computer Science · #Psychometric Methodologies and Testing #Bayesian Modeling and Causal Inference #Multi-Criteria Decision Making
paper · doi:10.1177/0013164406288165
openalex publication_date 2006/11/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/03
Coefficient alpha, the most commonly used estimate of internal consistency, is often considered a lower bound estimate of reliability, though the extent of its underestimation is not typically known. Many researchers are unaware that coefficient alpha is based on the essentially tau-equivalent measurement model. It is the violation of the assumptions required by this measurement model that are often responsible for coefficient alpha's underestimation of reliability. This article presents a hierarchy of measurement models that can be used to estimate reliability and illustrates a procedure by which structural equation modeling can be used to test the fit of these models to a set of data. Test and data characteristics that can influence the extent to which the assumption of tau-equivalence is violated are discussed. Both heuristic and applied examples are used to augment the discussion.