[R-pkgs] package 'ltm' -- version: 0.3-0

Dimitris Rizopoulos dimitris.rizopoulos at med.kuleuven.be
Tue Sep 27 10:56:13 CEST 2005

Dear R users,

I'd like to announce the new version of the package "ltm" (available 
from CRAN), for fitting Latent Trait Models (including the Rasch and 
two-parameter logistic models) under the Item Response Theory 
approach. Three main extra features have been added: (i) now both 
ltm() and rasch() permit general fixed-value constraints (e.g., useful 
for scaling purposes), (ii) there is the option to report the 
estimated parameters under the usual IRT parameterization, and (iii) 
both plot.ltm() and plot.rasch() are now more flexible. For info about 
other new features check the help and CHANGES files. Future plans 
include development of functions for fitting the three-parameter 
logistic and the graded response models. Any kind of feedback 
(questions, suggestions, bug-reports, etc.) is more than welcome.


Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://www.med.kuleuven.be/biostat/

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm

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