TAM Tutorials:  Home Page


1. Install R
2. Install TAM
3. Rasch Model
4. CTT, Fit
5. Partial Credit Model
6. Population Model
7. DIF

     *** Margaret Wu will conduct a workshop on TAM in Penang, Malaysia, on June 1-3, 2015.      For information, click on the link workshop pamphlet ***

TAM (Test Analysis Modules)     by T. Kiefer, A. Robitzsch & M. Wu

TAM is an R package written for IRT analyses. As an R package, TAM is open source and is completely free for download. TAM is an extremely flexible package, covering many IRT models. Analyses provided by TAM include the following:

  • Fit Rasch model using joint maximum likelihood method
  • Fit partial credit and generalised partial credit models
  • Fit facets models and perform DIF analyses
  • Compute fit statistics and standard errors
  • Use marginal maximum likelihood estimation method (MML)
  • Fit latent regression models
  • Fit multidimensional IRT models
  • Generate plausible values
  • Fit 2PL models

For researchers who are familiar with the ConQuest IRT software (Wu, Adams, Wilson & Haldane, 2007), TAM can perform nearly all of the ConQuest analyses. In many cases, TAM has extended ConQuest functionalities. Further, TAM runs a great deal faster than ConQuest for many analyses.

This website provides some tutorial materials for using TAM. The website is under development and is updated when new materials are available. For any queries about this website, please contact Margaret Wu via email

TAM package

TAM can be found at the R CRAN site which is the official R repository for packages.

For people unfamiliar with using R and R packages, the first and second Tutorials (see links on the left of this web page) provide instructions for the installation of R and the TAM package.


Wu, M. L., Adams, R. J., Wilson, M. R., Haldane, S.A. (2007).  ACERConQuest Version 2: Generalised item response modelling software.  Camberwell: Australian Council for Educational Research.