VPG is pleased to announce the immediate availability of IRTPRO™ Version 5.1 which includes bug fixes and a new ICC/TIF plot display control option in both the Advanced Options dialog and command line syntax. Users holding active IRTPRO™ subscription licenses are encouraged to upgrade, by logging into their account on the VPG Store and navigating to the License Detail record under My Account – Licenses – Manage.
VPG releases flexMIRT® Version 3.62
VPG is pleased to announce the immediately availability of flexMIRT® Version 3.62. Version 3.62 fixes a bug with multiple-group IRT modeling, and a labeling issue in output delivery. Importantly, Version 3.62 uses a completely new pseudo random number generator (PRNG), replacing the one that has been in use since flexMIRT 2.0. The new proprietary PRNG is based on the popular Mersenne Twister 19937 generator that substantially outperforms the PRNG used by flexMIRT previously. They will lead to slightly different results … Read More
VPG RELEASES FLEXMIRT® 3.6.1
VPG is pleased to announce the availability of flexMIRT® Version 3.6.1, which can be obtained through our webstore. The new version fixed several bugs with data import, nominal categories models, and cross-classified models. It also improved the support of covariates in MAP scoring for single level models. Users running version 3.6 are encouraged to upgrade at no cost.
VPG Releases flexMIRT® 3.6
VPG is pleased to announce the availability of flexMIRT® Version 3.6, 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.
Updates to IRTPRO Installer
We made minor bug fixes to the IRTPRO installer. The revised installer is available in the VPG Store for registered IRTPRO license holders by clicking on “Download Software” button within My Account – License tab.
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 irtpro.com to find out more about IRTPRO™. Visit our storefront at store.vpgcentral.com 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.
Vector Psychometric Group has acquired Scientific Software International, Inc.
Vector Software Acquisition, a sole subsidiary of Vector Psychometric Group, acquired Scientific Software International, Inc. expanding Vector’s statistical software offerings. Vector Psychometric Group (VPG), a leading provider of psychometric and data analytic solutions for clinical outcomes, educational, and psychological assessment, has acquired Scientific Software International, Inc. (SSI), a market-leader in statistical software for social, behavioral, and biostatistical sciences. SSI has been developing, publishing, and distributing specialized statistical software products since 1971. SSI has been a driving force behind many widely … Read More
VPG Awarded FDA Grant to Develop Clinical Outcome Assessments for Migraine
As part of our Patient Focused Drug Development (PFDD) efforts, the U.S. Food and Drug Administration (FDA) developed a pilot grant program to support the development of publicly available core set(s) of Clinical Outcome Assessments (COAs) and their related endpoints for specific disease indications (RFA-FD-19-006). On September 11, 2019 the FDA made three awards under this grant program. These awards will provide avenues to advance the use of patient input as an important part of drug development that can foster innovation and … Read More
Measurement invariance, the lack thereof, and modeling change
Edwards, M.C, Houts, C.R., & Wirth, R.J. (In Press). Measurement invariance, the lack thereof, and modeling change. Quality of Life Research.