Improving measurement in health education and health behavior research using item response modeling: Comparison with the classical test theory approach

Abstract

This paper compares the approach and resultant outcomes of item response models (IRMs) and classical test theory (CTT). First, it reviews basic ideas of CTT, and compares them to the ideas about using IRMs introduced in an earlier paper. It then applies a comparison scheme based on the AERA/APA/NCME 'Standards for Educational and Psychological Tests' to compare the two approaches under three general headings: (i) choosing a model; (ii) evidence for reliability-incorporating reliability coefficients and measurement error-and (iii) evidence for validity-including evidence based on instrument content, response processes, internal structure, other variables and consequences. An example analysis ..