Survey Statistics

Biography

Paul Biemer talks about his research in survey methodology

Biography

James Chromy discusses the art
of statistical analysis

Biography
Ralph Folsom, PhD and Chief Scientist for Statistical, Survey, and Computing Sciences at RTI, is an expert in the design and analysis of complex probability samples. Working on the National Survey on Drug Use and Health (NSDUH), Dr. Folsom initiated innovative weight adjustment methods based on his logistic response propensity and exponential poststratification models. Dr. Folsom also introduced model-based imputations for missing frequency of use and income data items, and he has been an influential collaborator in the development of NSDUH’s current Predictive Mean Neighborhoods (PMN) imputation methodology. Dr. Folsom has made significant contributions to the development of RTI’s computer software for survey data analysis, SUDAAN. These contributions include sample design-based modes of estimation and inference for linear and logistic regression coefficients. Read More…

Biography
Vincent G. Iannacchione, a senior research statistician, has been with RTI for over 22 years. He directs statistical operations for national surveys on health care, drug abuse, education, and military studies. He designs and selects samples, including multistage area and list sampling, network sampling, and double sampling for nonresponse. He directs the computation of sampling weights and the imputation of missing data, and he supervises data analysis. Read More…

Biography
Phillip S. Kott, PhD, is a senior research statistician and an expert in survey sampling theory and practice, including calibration weighting, multiphase sampling, the analysis of survey data, and variance estimation. Dr. Kott is a fellow of the American Statistical Association (ASA), a member of the International Statistical Institute, and a fellow of the Royal Statistical Society. He received a Presidential Rank Award in 2007 and an ASA Section of Statistics and the Environment Distinguished Achievement Medal in 1997. He is active as a journal associate editor, and served as the president of the Washington Statistical Society and the chair of ASA's Council of Chapters. He has taught survey sampling at George Mason University and the Joint Program in Survey Methodology. Prior to joining RTI in January 2009, Dr. Kott was the chief research statistician at the National Agricultural Statistical Service of the United States Department of Agriculture. Read More…

Biography
Karol Krotki, PhD, is a senior research statistician who joined RTI in 2004. His areas of specialization include survey research, social science data analysis, international studies, and demography. He is known nationally for his work in survey sampling, random-digit-dial telephone sampling, weighting, and alternative methods of survey design such as Internet panels. Dr. Krotki has held a number of honorary positions such as president of the Washington Statistical Society (2007-2010) and in 2008 was elected Fellow of the American Statistical Association. He has a number of publications and presentations to his credit, has held a variety of teaching positions, and is fluent in four languages. Read More…

Biography
Jay Levinsohn, PhD, has worked at RTI since 1974. He began his career in educational research by building large education databases from survey data. He then spent almost 15 years in information technology managing central computing services and assisting in the transition at RTI from mainframe computing to PC and PC server-based systems. In the last 8 years, he has been a department head in RTI’s Research Computing Division. He has over 30 years of experience in managing research projects, managing technical support services, and developing software applications. In the last several years, Dr. Levinsohn has focused on developing and deploying mobile computing systems. He has developed systems for the handheld Pocket PC to collect survey data in a variety of environments and for different applications. Read More…

Biography

Lee Rivers Mobley, PhD, Senior Fellow in health economics, appointed December 2008, specializes in spatial epidemiology and analysis of health care markets and behaviors, using spatial modeling, spatial econometrics, spatial decision support systems, and cartographical modeling. Dr. Mobley was named an RTI Fellow in 2005. She joined RTI in July 2001, and her work at RTI has included market analysis for several Medicare reform initiatives, spatial analysis to explain cardiac risk factors in low income women, and analysis of access to and utilization of preventive care services. Her research reveals why people disenroll from Medicare HMOs or don't get regular cancer screening. Dr. Mobley is currently funded by two NIH grants, and conducts analyses of disparities among populations and across geography, examining socioecological problems where place and space are important. Her research interests include behavioral modeling, measurement of the built environment, remote sensing as a resource for data development, gap or suitability analysis, and building spatial decision support systems.

Biography
Sally C. Morton, Ph.D., joined RTI in 2005 as vice president of statistics and epidemiology. Previously, Dr. Morton was head of the RAND Corporation Statistics Group from 1995 to 2002 and held the RAND endowed chair in statistics from 2000 to 2005. From 1997 to 2005, she was co-director of the Southern California Evidence-based Practice Center. Her methodological interests include the use of meta-analysis in evidence-based medicine, the sampling of vulnerable populations, and statistical methods for health services research. She is an editor of Statistical Science and served as an associate editor for the Journal of the American Statistical Association and the Journal of Computational and Graphical Statistics. Dr. Morton is a fellow of the American Statistical Association and of the American Association for the Advancement of Science. Read More…

Biography
Roy Whitmore, PhD, is a senior statistician who joined RTI in 1980. He is expert in design and analysis of complex sample surveys. His primary areas of application have been human exposure assessment surveys and postsecondary education studies. He recently was principal investigator for an EPA STAR grant that developed a data collection platform for human exposure-related behaviors, including time/activity/location/exertion-level data, dietary data, and data on use of consumer products. He was sampling task leader for such high-visibility EPA studies as the EPA Region 5 field test of the National Human Exposure Assessment Survey. He has served as task leader for sampling, weighting, imputation, and reporting for several postsecondary education surveys for the National Center for Education Statistics. He has published in the Journal of Exposure Science and Environmental Epidemiology, Environmental Health Perspectives, Environmental Science and Technology, Atmospheric Environment, Journal of Official Statistics, and Journal of the American Statistical Association. Read More…

Biography
Rick L. Williams, PhD, has over 25 years of experience in public health research as a statistician. He designs population surveys, observational studies, and randomized trials, and develops and applies analysis methods for correlated and sample survey data. For six years he led the development of SUDAAN^®, RTI’s software package for the analysis of correlated data. Dr. Williams has extensive experience with health studies of women and children. He is active in the safety assessment of pharmaceutical and agricultural compounds, especially developmental and reproductive toxicology. Health outcome and epidemiological studies are other areas of his expertise. Dr. Williams has authored numerous research protocols, study reports, presentations, and refereed articles in publications such as Biometrics, Lifetime Data Analysis, and the Journal of the American Medical Association. He was selected by a peer-review committee to serve as a Fellow for one year at the Statistical Survey Institute of the U.S. Department of Agriculture. Read More…