I am interested in measurement issues in the social sciences. Much of my work has been in the realms of item response theory (IRT) and factor analysis. Topics I'm currently working on include: multidimensional IRT (a.k.a. item factor analysis) models, minimum detectable change, multi-stage adaptive testing, measurement models for multiple reporters, local dependence diagnostics, and model fit (and misfit). In addition, I have developed software to allow researchers to estimate item factor analysis models using MCMC.
I am also very interested in the growing application of psychometrics in the realm of patient reported outcomes (PROs).