This book and BIOMETRY by Sokal and Rohlf are the two standard statistics books that live on the shelves of most biological researchers. Zar makes methods and interpretations of statistical analyses accessible and understandable. There are suffient numbers of statistical tests in the text to cover most of my statistical needs. The book also includes its own tables of critical values (something that BIOMETRY does not -- there's a paperback companion book of tables for that book). Zar also includes examples that are easy to follow, as well as enough mathematical background to allow one to understand the hypothetical and much of the mathematics behind the statistical methods. I typically turn to Zar first when I have a statistical question. This book continues to be a highly prized ally of mine in the data analysis game. I highly recommend this book to all biology grad students and researchers. It's well worth the price -- an investment that pays off! 5 stars, no doubt about it.