Vector Psychometric Group (VPG) is proud to offer cutting-edge software for web-based data collection and item response data analysis. Authored by Li Cai, one of the leading experts in psychometrics, Adaptest®, IRTPRO™, and flexMIRT™ have state-of-the-art features unavailable in other programs. Adaptest®, our web-based computerized adaptive testing (CAT) engine, has been updated to a “plug-in,” allowing any existing electronic data collection system (EDC) to administer adaptive tests and provide real-time scoring with minimal modifications. IRTPRO™, with its intuitive graphical user interface, built-in data management capacity, high quality graphics, and a professional HTML-based output delivery system, have become widely adopted by educators, researchers, and assessment professionals. flexMIRT™, VPG’s flagship IRT software, has some of the richest psychometric and statistical features defining the state of the art. With the ability to be installed and called remotely, flexMIRT™ is ideal for the individual analyses of an applied researcher or the large-scale analyses and scoring needed for operational use.
Adaptest® from VPG allows research teams to use a range of outcome measures from single-item responses to the most advanced item response theory-based assessments. Adaptest® is easy to implement from full integration in the host system to a simple JavaScript plugin. Adaptest® can run on any Microsoft or Linux system and easily scales on the Amazon Elastic beanstalk. Regardless of the method, Adaptest® is able to easily integrate into most existing EDC systems, allowing them to administer items adaptively, if desired, and provide real-time scoring with minimal programming changes.
flexMIRT™ is software specifically designed for the analysis of item response data, such as what can be obtained from a quality of life measure, attitude survey, or academic test. It is able to accommodate a wide variety of IRT models to factor structures that are both unidimensional and multidimensional (e.g., the items measure more than one concept). flexMIRT™ provides a wide variety of item and model fit statistics and indices for evaluating results and produces several different types of IRT-based scores, depending on user request. While flexMIRT™ is primarily a confirmatory modeling program, it has capabilities for performing EFA with analytic rotations as well. To purchase a flexMIRT™ subscription, please visit store.vpgcentral.com.
We understand that the end-users’ institutions may have additional regulatory and compliance requirements that necessitate changes to the end-user license agreement. Additional fees will be assessed if changes are proposed to cover the cost of negotiations.
IRTPRO™ is an advanced application for item calibration and test scoring using item response theory (IRT). It comes with an intuitive graphical user interface and offers built-in production quality IRT graphics. Suitable for educators, students, researchers, and assessment organizations, IRTPRO™ has become increasingly popular in the educational, psychological, social, and health sciences. IRTPRO™ handles any combination of unidimensional or multidimensional versions of popular IRT models, in multiple groups. The users may choose from a number of sophisticated estimation algorithms for item and person parameters. User-defined parameter restrictions and the availability of many test statistics facilitate statistical inference for IRT modeling. To purchase a IRTPRO™ subscription, please visit store.vpgcentral.com
We understand that the end-users’ institutions may have additional regulatory and compliance requirements that necessitate changes to the end-user license agreement. Additional fees will be assessed if changes are proposed to cover the cost of negotiations.
We are happy to announce that in early 2020, Scientific Software International Inc. (SSI), has become a wholly owned subsidiary of Vector Psychometric Group, LLC. All of SSI’s statistical programs has been migrated to a new subscription-based software delivery and support model called SSI Live™.
VPG also offers clients the opportunity to customize Adaptest® or flexMIRT™, creating software that is built to meet your specific needs. Please contact us at sales@vpgcentral.com for more information about how Adaptest® and flexMIRT™ can be put to work for you.
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Currently we offer no native Mac version of any of our programs currently available. However, if you have a dual-boot set-up or a Windows emulator, any of our programs should run without issues as long as your hardware is not using Apple’s proprietary ARM-based chips because of known compatibility issues. Note that we can only provide support for using the software and are unable to provide guidance on setting up a Mac to allow for a program to be usable. Parallels Desktop is the most frequently used of the emulators. VirtualBox is a free alternative from Oracle, but it can be very slow compared to Parallels.