Welcome to the BradleyTerry2 project!

BradleyTerry2 is a package designed to facilitate the specification and fitting of Bradley-Terry models for pair comparison data, including structured versions where there are explanatory variables predicting the latent "ability" (or "worth") parameters.

The authors are Heather Turner and David Firth.

Further information

• Overview of BradleyTerry2 (PDF)
• Slides (PDF) for a talk given at the 2nd Workshop on Psychometric Computing, Munich, February 2010.

Package history and availability

This package was first released as version 0.9-1 (2010-02-23).

The sources and windows binary for the current version are available at CRAN sites for installation into R in the standard way.

The development version can be found from the R-forge project summary page.

The BradleyTerry2 software is made available free, under GPL version 2. It comes with ABSOLUTELY NO WARRANTY.

This package is a substantial development of the earlier BradleyTerry package, which is now obsolete. The user interface of BradleyTerry2 is different (and much more general), hence the need to change the name of the package.