flexMIRT^®– The most advanced IRT software available

A multilevel, multidimensional, and multiple group item response theory (IRT) software package for item analysis and test scoring. flexMIRT^® fits a variety of unidimensional and multidimensional item response theory models (also known as item factor analysis models) as well as diagnostic classification models to single-level and multilevel data in any number of groups.

flexMIRT^® is easy to use

Windows-based flexMIRT^® has a graphical user interface (GUI) and is available in both 32-bit and 64-bit versions. It has an intuitive syntax and can be run seamlessly in a command line mode for high volume production. The user’s manual demonstrates a variety of analyses with annotated input and output.

flexMIRT^® is flexible

Our IRT software can fit a wide variety of item-level models including 1PL, 2PL, 3PL, Graded Response Model, Generalized Partial Credit Model, and Diagnostic Classification Models. It is able to accommodate multiple dimensions, dependence within the data (i.e., multilevel), crossed random effects, covariates, and departures from normality in the latent trait(s).

flexMIRT^® is fast

As modern CPU architecture trends toward multi-core design, flexMIRT^® uses parallel processing to further speed up computations by spreading the load automatically to the multiple available cores or processing units. When possible, flexMIRT^® uses dimension reduction to automatically reduce the number of dimensions of integration for multidimensional or multilevel models.

flexMIRT^® can handle large datasets

A newly-designed memory allocation scheme helps flexMIRT^® efficiently handle thousands of items and millions of respondents. Great for any size analysis where item response theory models are needed.