Ray's unique philosophy of science approach focuses on two major goals: Introducing students to the basics of science and to the spirit that motivates many scientists; and helping students make the transition from outside observer of science to active participant. Although most students grasp the idea of asking testable questions, they often have an uncertainty of what exactly it is they are testing in research. To help clarify this point, Ray has presented the process of hypothesis testing both conceptually and practically. This information is important not only for those who seek a career in research, but also for anyone who wishes to understand the daily headlines involving scientific research. To help faculty teach this course and to help students understand the material better, Ray has made a special effort to define and illustrate general problem areas for students. These areas include concept of interaction effect, interpretation of interaction effects, meaning of causation in science and the use of the terms error and chance in relation to experimentation. In addition, Ray includes end-of-chapter summaries, with questions to test and integrate the material presented in the chapter This additional emphasis in clarifying more important concepts will help students walk away with a handle on key concepts of the course.