This page gives links to some software I have written that is freely available for downloading.

The following are some C++ source code libraries which I use for numerical applications.

- Estimation Toolkit for Item Response Models (ETIRM) A set of C++ classes and functions that can be used for estimation of item response models using the EM algorithm.
- Simple C++ Numerical Toolkit (SCPPNT) - This is a modification of the Template Numerical Toolkit that I am using for several numeric programming projects. SCPPNT contains matrix and vector classes modified from those in TNT.
- Uncmin++ - C++ implementation of the UNCMIN routines for unconstrained optimization.

- IRT Command Language (ICL) - Application that can perform single- or multiple-group estimation of the 1-, 2-, and 3-parameter logistic item response models for dichotomous items, and the partial credit model and generalized partial credit model for polytomous items. ICL supercedes the Estimation Program for Dichotomous Item Response Models (EPDIRM) by including estimation of polytomous as well as dichotomous models.
- Equating with the Multiple-Choice Model - Applications to perform equating (IRT scale transformation) for the multiple-choice and nominal response models as described in this paper. Compiled versions of these programs are available for Windows 95/NT. The source code is also available.
- Equating Software - Some test equating software for Mac OS and Windows 95 that I helped to write is available from the Iowa Testing Programs.

- BBEdit Plug-Ins - I have written some plug-ins for the Macintosh text editor BBEdit that allow it to interact with two other Macintosh programs: MacPerl (an implementation of the Perl programming language), and Textures (an implementation of the TeX typesetting language).

Sofware by Brad Hanson

Last updated: October 15, 2006 (ww)