ABSTRACT
In Chapter 12, the discussion transitions from considering one variable at a time to the relationship between two or more variables. Analysis of relationships between variables involves (1) testing for statistical significance and (2) measuring the strength and direction of the relationship. Chapter 12 addresses the first of these. The chapter discusses the meaning of statistical significance, why researchers test for it, and alternatives to it. Topics include the stating of null and research hypotheses, types of errors, and power.
Three tests of statistical significance and their uses are discussed. These include chi-square, t-test, and analysis of variance. When and how each is to be used is explained and illustrated with examples. Details on the calculation of chi-square and t-tests are included in sections separate from the narrative explanations so readers can allocate time to each as they wish. How to apply and interpret the results of tests of statistical significance are explained. A section of the chapter is devoted to the distinction between statistical and practical significance of research findings.
