Book excerpt: SAS Essentials provides an introduction to SAS statistical software, the premiere statistical data analysis tool for scientific research. Through its straightforward approach, the text presents SAS with step-by-step examples. With over fifteen years of teaching SAS courses and over fifty combined years of teaching and consulting by the authors, this valuable reference presents data manipulation and statistical techniques, including a website with examples. This textbook is essential for teachers because the chapters are self-contained and may be used accordingly to the teacher?s preference, whether for a one-semester or two-semesters course.