tailieunhanh - Ebook The essentials of statistics - A tool for social research (2nd edition): Part 2

(BQ) Part 1 book "The essentials of statistics - A tool for social research" has contents: Association between variables measured at the interval ratio level; association between variables measured at the interval ratio level; introduction to bivariate association and measures of association for variables measured at the nominal level; partial correlation and multiple regression and correlation. | 10 LEARNING OBJECTIVES Hypothesis Testing III The Analysis of Variance By the end of this chapter, you will be able to: 1. Identify and cite examples of situations in which ANOVA is appropriate. 2. Explain the logic of hypothesis testing as applied to ANOVA. 3. Perform the ANOVA test, using the five-step model as a guide, and correctly interpret the results. 4. Define and explain the concepts of population variance, total sum of squares, the sum of squares between, and the sum of squares within, and mean square estimates. 5. Explain the difference between the statistical significance and the importance of relationships between variables. INTRODUCTION In this chapter, we will examine a very flexible and widely used test of significance called the analysis of variance (often abbreviated as ANOVA). This test is designed to be used with interval-ratio level dependent variables and is a powerful tool for analyzing the most sophisticated and precise measurements you are likely to encounter. It is perhaps easiest to think of ANOVA as an extension of the t test for the significance of the difference between two sample means, which was presented in Chapter 9. The t test can be used only in situations in which our independent variable has exactly two categories (., Protestants and Catholics). The analysis of variance, on the other hand, is appropriate for independent variables with more than two categories (., Protestants, Catholics, Jews, people with no religious affiliation, and so forth). To illustrate, suppose we were interested in examining the social basis of support for capital punishment. Why does support for the death penalty vary from person to person? Could there be a relationship between religion (the independent variable) and support for capital punishment (the dependent variable)? Opinion about the death penalty has an obvious moral dimension and may well be affected by a person’s religious background. Suppose that we administered a scale that measures