Scientific Software International Inc. (SSI), a wholly owned subsidiary of Vector Psychometric Group, LLC, a North Carolina-based software and consulting company, welcomes you to SSI Live™.
With your renewable SSI Live™ subscription, you are entitled to many more benefits in comparison to previous SSI software licensing models. Click here to view a side-by-side comparison chart of features, including exclusive educator benefits. Selected 14-day SSI Live™ Trial subscription remains freely available for a potential user’s evaluation purposes.
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.
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.
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.
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.
HLM provides statistical tools for comprehensive hierarchical data modeling. A recent addition to this popular program is the option to estimate an HLM from incomplete data, using a completely automated approach that generates and analyses multiply imputed data sets from incomplete data.
LISREL provides tools for structural equation modeling, data manipulations and basic statistical analyses, hierarchical and non-linear modeling, generalized linear modeling, and generalized linear modeling for multilevel data.
SuperMix is an application for comprehensive mixed-effect modeling and combines the functionality of four mixed-effects programs, MIXREG, MIXOR, MIXNO, and MIXPREG into a single application to provide estimates for mixed-effects regression models.
BILOG-MG is an extension of BILOG that is designed for the efficient analysis of binary items, including multiple-choice or short-answer items scored right, wrong, omitted, or not-presented. BILOG-MG is capable of large-scale production applications with unlimited numbers of items or respondents.
PARSCALE implements Item Response Theory (IRT) measurement methods for binary, multiple-category and rating-scale items. The flexibility and the wealth of information provided by this program have kept it in regular use by researchers around the world.
Auxal performs both structural and nonstructural auxological analysis of human growth in standing height or recumbent length.