This revised edition explains various aspects of research methodology in science. Various philosophies of science that are necessary to understand the basic principles of research, scientific method, publication of research articles, preparation of research thesis, etc. are described with all necessary details. Detailed discussion on various research and publication ethics is given. The book includes various topics in the syllabi of PhD coursework on research methodology in science and mathematics of many Universities. This book will help the reader to understand the topics in a better way. Detailed discussions, examples, and proper illustrations are provided wherever necessary.