PolyCov
A program to compute item parameter covariances from a polytomous IRT analysis.

The program reads an IRT parameter file and computes covariance of item parameters for the Graded Response Model using the approach described in

Morris, S. B., Fortmann-Johnson, K., and Oshima, T.C. (2007). An Evaluation of the Item Parameter Replication Method for DFIT Analysis of Polytomous Items. Paper presented at the annual conference of the National Council of Measurement in Education, Chicago, IL.

This software is copyright (c) 2009 by Dr. Scott B. Morris. It available free for research or educational purposes. For written permission to use it for any other purpose, please contact Scott B. Morris, College of Psychology, Illinois Institute of Technology, 3105 S. Dearborn, Chicago, IL 60616. Email: scott.morris@iit.edu

Download Program

SAS Macro

The calculations have also been implemented as a SAS Macro, written by,
Pengsheng Ni
Health & Disability Research Institute
Boston University School of Public Health
Boston, MA
psni@bu.edu

Download SAS Macro

Please direct questions regarding the SAS Macro to psni@bu.edu.

PCMCov
A program to compute item parameter covariances from the Generalized Partial Credit Model.

The program reads an IRT parameter file and computes covariance of item parameters for the Generalized Partial Credit Model using the approach described in

This software is copyright (c) 2009 by Dr. Scott B. Morris. It available free for research or educational purposes. For written permission to use it for any other purpose, please contact Scott B. Morris, College of Psychology, Illinois Institute of Technology, 3105 S. Dearborn, Chicago, IL 60616. Email: scott.morris@iit.edu

Download Program

 

Problems?

Contact me at scott.morris@iit.edu

Return to My Home Page

Scott Morris ( scott.morris@iit.edu )