Ron Cody, EdD, a retired professor from the Robert Wood Johnson Medical School now works as a private consultant and a national instructor for SAS Institute Inc. A SAS user since 1977, Ron's extensive knowledge and innovative style have made him a popular presenter at local, regional, and national SAS conferences. He has authored or co-authored numerous books, such as Learning SAS by Example: A Programmer's Guide; SAS Statistics by Example, Applied Statistics and the SAS Programming Language, Fifth Edition; The SAS Workbook; The SAS Workbook Solutions; Cody's Data Cleaning Techniques Using SAS, Second Edition; Longitudinal Data and SAS: A Programmer's Guide; SAS Functions by Example, Second Edition, and Cody's Collection of Popular Programming Tasks and How to Tackle Them, and Test Scoring and Analysis Using SAS, as well as countless articles in medical and scientific journals.