PARSCALE

PARSCALE is a software tool designed to analyze test response data based on item response theory (IRT) models. In the early 1990s, Eiji Muraki and R. Darrell Bock first developed the initial version of PARSCALE for the DOS platform. The latest version, PARSCALE 4.1 for the Microsoft Windows platform, is commercially available from Scientific Software International, Chicago, IL. There also is a modified version of PARSCALE for the UNIX platform, which is customized mainly for internal use at Educational Testing Service.

PARSCALE was one of the few software tools available in the 1990s and early 2000s for analyzing ordered polytomous response data, such as Likert-type rating scale responses and graded response data. The program supports several different IRT models for polytomous data including the graded response ...