TiaPlus

TiaPlus is a Windows (Windows 95 or higher) program for test and item analysis within the framework of Classical Test Theory (CTT). The program offers flexibility in scoring the item answers and can handle missing values, subgroups and subtests, and tests that have mixed types of items (item formats, answer formats).

TiaPlus also allows for DIF analysis, creates both numerical and graphical analysis results, and can report numerous item- and test characteristics, among which the GLB (Greatest Lower Bound coefficient) that gives the optimal estimate for test reliability.