This is the third edition of this popular textbook. The first and second editions were extremely well received by both students and lecturers alike and have helped to simplify the often complex and difficult task of choosing and using the right statistics package. This is a book for any student or professional biologist who wants to process data using a statistical package on the computer, to select appropriate methods, and extract the important information from the often confusing output that is produced. It is an ideal text for undergraduates and masters students in the biological sciences who have to apply statistics in practical classes and projects. Such users of statistics do not have to understand either how tests work or how to do the calculations, and these aspects are not covered in the book.