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Using the GLIMMIX Procedure in SAS 9.3 to fit a standard dichotomous Rasch and Hierarchical 1-PL IRT Model

Based on a recent study, our team has published an article in the “Applied Psychological measurement” journal titled, “Using the GLIMMIX Procedure in SAS 9.3 to fit a standard dichotomous Rasch and Hierarchal 1-PL IRT Model.” To access the full text, click here.

Abstract
Although Rasch models have been shown to be a sound methodological approach to develop
and validate measures of psychological constructs for more than 50 years, they remain underutilized
in psychology and other social sciences. Until recently, one reason for this underutilization
was the lack of syntactically simple procedures to fit Rasch and item response theory (IRT) models
in general statistical software packages. In this article, the authors demonstrate how to fit
the standard dichotomous Rasch model and a dichotomous one-parameter logistic IRT model
with nested random effects via the easy-to-use GLIMMIX procedure in SAS 9.3. For comparison
purposes, the standard dichotomous Rasch model was also fit using the Rasch specialized software,
WINSTEPS 3.68.2. The SAS code used to simulate the data on which the Rasch model
was fit is provided to allow replication of estimates. Findings suggest that the GLIMMIX procedure
may be a viable option for fitting the standard dichotomous Rasch and dichotomous IRT
models.

Keywords

standard dichotomous Rasch model, dichotomous 1-PL IRT model with nested random effects,
item response theory, IRT, SAS 9.3, GLIMMIX

To obtain the full text, click here.