This page represents Ben-Roy Do's personal response to some questions asked by IRT tutorial web site visitors since July 2005. This section is currently under construction and will be updated from time to time. If you have IRT tutorial web site related questions, please send an e-mail to Ben-Roy Do. This page is for reference only.
A. General questions
B. Data preparation questions (e.g., SPSS)
C. Investigation of Dimensionality questions (e.g., SYSTAT)
D. IRT Models questions (e.g., BILOG, BILOG-MG, MULTILOG7)
E. Model-data Fit questions (e.g., MODFIT)
F. DIF/DTF questions (e.g., ITERLINK)
Note: To receive the latest copy of MODFIT (Stark, 2007), please contact Professor Stephen Stark at University of South Florida,