jMetrik is a free and open source computer program for psychometric analysis. Methods include classical item analysis, differential item functioning, item response models (e.g. Rasch, 3PL, 4PL, GPCM), and item response theory linking and equating. Click here for a list of features.
IRT Illustrator is a pure Java application that allows you to quickly plot various item response theory functions. It currently support the Rasch, 2PL, 3PL, and 4PL binary item response models and the partial credit (PCM), generalized partial credit (GPCM), and graded response (GRM) models. Once you have created a chart, save it as either a PNG or JPG file.
We offer custom software solutions, educational measurement workshops, and psychometric consulting services. Contact us for more information.
Open Source Software
We are firm believers in the value of open source software. Transparency is not only good for psychometricians and statisticians who would like to verify computational procedures, but it is also good for longevity. Software should have a life beyond its original developer and should be available in ways that foster innovation. All of our source code is publicly available at GitHub. Click here to view it.