ABSTRACT
IRTPRO (Cai et al., 2011) is a completely new software program for item calibration and test scoring based on item response theory (IRT) methods. The development ofIRTPRO began in 2005 as part of a Phase I Small Business Innovative Research (SBIR) contract awarded to Scientific Software International (SSI) from the National Cancer Institute (contract# HHSN-2612007-00013C). The background of the SBIR funding was set in the rapidly changing requirements expected of IRT software programs that are motivated, among others, by the National Institutes of Health's (NIH) agency-wide Patient-Reported Outcomes Measurement Information System (PROMIS) initiative, which relies heavily on IRT methods.
