This book brings forward the various concepts of statistical techniques used in clinical research, starting from the basics of research design to principles of data collection and their analysis. Relevant topics such as classification of data, various study designs, sample size determination, randomization etc have been covered in detail. Though details of the various tests have not been included but special emphasis has been given to the concept of sensitivity and specificity and its clinical application as it is one of the most useful and frequently used statistical tool in clinical research.The material in this book assumes that the reader is familiar with basic applied statistics, but still every possible attempt has been made to simplify the details of the text and to create a strong concept that will make it easy to read and comprehend.In this text book we have emphasized on "how to" rather than the theoretical aspect; however, on several occasions the theory behind certain topics could not be omitted, but is presented in a simplified form. The concepts laid down in this book will be of enormous help in formulating a research project and carrying it forward to its completion.