Progress in the technology of measurement: Applications of item response models.

Abstract

Despite advances in psychometric theory and analytic techniques, a number of issues regarding the assessment of depression remain unresolved, including the relative effectiveness of response options (option effectiveness), the ability of existing measures to detect differences in depressive severity (scale discriminability), and the extent to which certain groups of individuals use items and options differently (differential item functioning). One part of the article introduces the fundamentals of nonparametric item response models; the 2nd part of the article illustrates how item response models can be applied to address specific psychometric issues. Although the article focuses on the assessment of depression, the problems addressed in this article are present in virtually every field of psychological research, and the techniques offered may be applied broadly. Analytic techniques based on item response models are not only helpful in identifying and ultimately resolving many of these issues, they are essential to ensure that traits, abilities, and conditions, such as depression, are assessed fairly and equitably.