Mary D. Sammel Sc.D.
Professor of Biostatistics in Biostatistics and Epidemiology at the Hospital
University of Pennsylvania
Dr. Sammel's statistical specialties are in the area of multivariate and longitudinal data methods, as well as analysis of mixtures of discrete and continuous data. Research content areas of interest include environmental and reproductive health. Dr. Sammel has extensive experience as a data analyst and has worked with a variety of biomedical investigators.
Dr. Sammel's current work is in the area of latent variable modelling where the focus is to reduce multivariate data to a smaller number of dimensions and estimate the impact of covariates. This is one way to address the issue of multiple testing for multivariate data. It also provides a means for producing a relative ranking of the subjects with respect to the latent variable. Current manuscripts in progress will evaluate the performance of this global test to standard methods. Work is also in progress to expand programs to deal with ordered categorical responses which are commonly used to develop health scales.