The purpose of this book is to introduce the clinical researcher to the concepts of physiologic computer modeling and the systems analysis approach to research investigations. The book is geared toward a clinical researcher with limited experience in modeling and the techniques of systems analysis, and it provides a broad overview of the subject and some instruction in basic modeling building and solution techniques based upon a course currently taught by Dr Coleman for graduate students. A large emphasis of the book is to provide the reader with a practical understanding of what modeling can do to enhance their research activities and give insight into the systems analysis approach to research questions. Examples are provided to demonstrate the use of modeling and systems analysis techniques in the solution to common clinical research questions.