In many areas of research, the precise measurement of hypothesized processes or variables (theoretical constructs, latent variables) poses a challenge by itself. In social sciences, unreliable measurements of people’s beliefs or intentions obviously hamper efforts to predict their behavior. Each measurement (response to an item) reflects to some extent the true score for the intended concept an...

Researchers in marketing, organization behaviour, and the other fields of business research frequently study variables that are abstract and not directly observable, for example, country image, brand loyalty, service quality, job satisfaction, work stress, managerial competence, etc. To measure such variables, referred to herein as latent variables, latent traits, or constructs, a multiple-item...

Historically, reliability issues in psychology and education have been addressed principally using classical test theory (CTT), which postulates that an observed score can be decomposed into a “true” score and a single, undifferentiated random error term, E (Feldt & Brennan, 1989). Generalizability (G) theory liberalizes CTT by providing models and methods that allow an investigator to disentan...

article distributed under the terms of the Creative Commons Attribution License which permits unrestricted use of work provided the original work is properly cited. General Medical Council (GMC) in the UK has emphasized the importance of internal consistency for students' assessment scores in medical education. 1 Typically Cronbach's alpha is reported by medical educators as an index of interna...

Current interest in the assessment of measurement equivalence emphasizes 2 major methods of analysis. The authors offer a comparison of a linear method (confirmatory factor analysis) and a nonlinear method (differential item and test functioning using item response theory) with an emphasis on their methodological similarities and differences. The 2 approaches test for the equality of true score...

This article provides analytic evaluations of population true-score measures for binary items given their item response theory (IRT) calibration. Under the assumption of normal trait distribution, the expected values of marginalized true scores, error variance, true score variance, and reliability for norm-referenced and criterion-referenced interpretations are presented as a function of the it...