I am an Emeritus Professor of Biostatistics. I have expertise in the development and use of statistical methods for longitudinal data analysis, mixed models and latent class models. I am the co-author of the Wiley texts Variance Components and Generalized, Linear, and Mixed Models (now in its second edition), the Springer text Regression Methods in Biostatistics (now in its second edition) and the author of the Institute of Mathematical Statistics monograph, Generalized Linear Mixed Models. I am a fellow of the American Statistical Association and an elected member of the International Statistical Institute and have over 40 years of statistical consulting experience.