Gary G. Koch, PhD, is Professor of Biostatistics and Director of the Biometrics Consulting Laboratory at the University of North Carolina at Chapel Hill. He has been active in the ...view moreGary G. Koch, PhD, is Professor of Biostatistics and Director of the Biometrics Consulting Laboratory at the University of North Carolina at Chapel Hill. He has been active in the field of categorical data analysis for fifty years. Professor Koch teaches classes and seminars in categorical data analysis, consults in areas of statistical practice, conducts research, and trains many biostatistics students. He is coauthor of Categorical Data Analysis Using SAS ®, Third Edition.view less