The book is a reference book useful for undergraduates, postgraduates and research scholars of biological, ecological and medical sciences. The purpose of writing this book is to provide an accessible reference book on statistical techniques whose proper use will help students in withdrawing accurate results and able to interpret them logically. The methods described in this book are, of course, the same as those used in different disciplines, but things are made so user's friendly that even general readers will find this book useful. The s of the book have been organized in such a way that suits the course curriculum of various universities. In this book enough materials are provided to cover statistical techniques with examples which are ecological and biological based.