Washington University School of Medicine

Division of Biostatistics
Seminar Series Fall 2009

Unidimensional Item Response Theory with Estimation of the Latent Density

Carol M. Woods
Center for Applied Statistics and Psychology
Washington University in St. Louis

Friday, September 25, 2009, 12:30–1:30 pm

GEMS classroom, 3rd Floor in Shriner's Building
Coffee, tea, and cookies will be provided


Abstract

This talk describes a program of research related to the distribution of the random latent variable in unidimensional item response theory (IRT), when the model is estimated using marginal maximum likelihood estimation. Often, the latent variable is presumed to follow a normal distribution, but this may not be tenable for all problems. Two key methods for fitting these models wherein the latent density is estimated simultaneously with the item parameters instead of presumed normal are described and evaluated.