SAS, which was originally called the Statistical Analysis System, is a statistical software package that runs on both PC and UNIX platforms as well as on other mainframe computers. Growing out of a project aimed at management and analysis of agricultural experiments in the Department of Experimental Statistics at North Carolina State University in the late 1960s, SAS has evolved into an integrated system of data management and decision support tools. SAS can perform data entry, retrieval, management, and mining; graphics generation and reporting; statistical analysis; business planning, forecasting, and decision making; operation research and project management; and quality improvement. Although SAS offers a point-and-click front end (the windows-based graphic user interface [GUI]) to users not familiar with the SAS language, SAS programming provides more ...