In this revision of his best-selling text, William Ray takes a broad, "philosophy of science" approach, introducing students to the basics of doing science and to the spirit that motivates scientists. Acclaimed in the field for its clarity, comprehensiveness, and accuracy, the text helps students see how scientists get their ideas for their studies and how ideas are turned into testable hypotheses. Ray is noted for his ability to present difficult concepts in a clear, straightforward fashion and for his excellent use of examples and graphs to make concepts easy to understand. For example, he not only illustrates the concept of interaction effect with research examples, he also graphically represents numerous possible outcomes.