RELIABILITY AND GENERALIZATION STUDIES RELIABILITY: ARGUMENTS FOR MULTIPLE PERSPECTIVES AND POTENTIAL PROBLEMS WITH GENERALIZATION ACROSS STUDIES

The present article addresses reliability issues in light of recent studies and debates focused on psychometrics versus datametrics terminology and reliability generalization (RG) introduced by Vacha-Haase. The purpose here was not to moderate arguments pre-sented in these debates but to discuss multiple perspectives on score reliability and how they may affect research practice, editorial policies, and RG across studies. Issues of classical error variance and reliability are discussed across models of classical test the-ory, generalizability theory, and item response theory. Potential problems with RG across studies are discussed in relation to different types of reliability, different test forms, different number of items, misspecifications, and confounding independent vari-ables in a single RG analysis. The editorial policies of Educational and Psychological Measurement (EPM) have become a focal point of recent studies and debates related to im-portant issues of reliability, effect size, and confidence intervals in reporting research. The purpose of this article was not to reiterate or moderate datametrics-psychometrics arguments presented in these debates (e.g.