Do not read this book If you are not interested in understanding medical research process to be able to share in producing and consuming knowledge about the human body. If you are already an expert in medical research. This book is for entry level medical researchers. It focuses on basics and lead you to a level in which you can: do simple research alone, do more complicated researches under supervision or be ready to complete your self-learning. If you are - or want to be - a statistician. This book targets medical under/postgraduates. All topics and examples are tailored for them. If you are seeking a family-size text book covering all topics of medical research. This book stops half way to the top, as we think that the rest can be found on other more sophisticated sources that won't be hard to understand anymore after you finish our book. If you need to know the theory behind everything. This book is written by clinicians who do researches and train others to do so. We focused on how-to-do and what does this mean, but not on the mechanisms and boring equations. We are not that geeky, yet