Introducing IRTPRO™ Version 5.0

VPG is pleased to announce that with the acquisition of Scientific Software International, Inc. in early 2020, IRTPRO™ Version 5.0 is being released under a new subscription-based software delivery and support model. A popular IRT software program for both patient-reported outcomes analysis and educational assessment development, this latest upgrade release offers significant new features and improvements.  Please visit to find out more about IRTPRO™.  Visit our storefront at to learn more about licensing and to make a purchase.

VPG Releases flexMIRT® 3.6 Release Candidate

VPG is pleased to announce the availability of flexMIRT® Version 3.6 Release Candidate, which can be obtained through our webstore. flexMIRT® Version 3.6 offers an improved user-friendly GUI and substantially upgraded statistical modeling capabilities, including new model fit indices, multidimensional models with non-normal latent densities, Markov chain Monte Carlo (MCMC) estimation, crossed random effects, and improved diagnostic classification modeling.