Scores estimated from multidimensional item response theory (IRT) models are not necessarily comparable across dimensions. In this article, the concept of aligned dimensions is formalized in the context of Rasch models, and two methods are described--delta dimensional alignment (DDA) and logistic regression alignment (LRA)--to transform estimated…

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…

Standardizing the measurement tools that researchers use to assess the effectiveness of interventions would strengthen our ability to compare results across studies. In practice, however, standardization is difficult to implement, in part, because researchers prefer to use measurement tools that focus specifically on the components of their…

When measuring participant-reported attitudes and outcomes in the behavioral sciences, there are many instances when the common measurement assumption of unidimensionality does not hold. In these cases, the application of a multidimensional measurement model is both technically appropriate and potentially advantageous in substance. In this paper,…

Structure of the Observed Learning Outcome (SOLO) science superitems were examined from the perspectives of Guttman Scaling (deterministic) and Item Response Theory (probabilistic). Differences between the measurement bases for the two approaches, and the results for a small case study, are reported. (Author/MLW)