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. Best, Dimitris ---- 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/ http://www.student.kuleuven.be/~m0390867/dimitris.htm Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm _______________________________________________ R-packages mailing list R-packages at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-packages