市场营销调研教学资料 2015 chapter 15.pptVIP

LEARNING OUTCOMES Choose the appropriate statistic Construct a cross-tabulation table and the corresponding χ2 statistic Use a t-test to compare a difference between two means Conduct a one-way analysis of variance test (ANOVA) Appreciate the practicality of modern statistical software packages Use the GLM to represent a generalized statistical model After studying this chapter, you should be able to What Is the Appropriate Test of Difference? Test of Differences An investigation of a hypothesis that two (or more) groups differ with respect to measures on a variable. Behavior, characteristics, beliefs, opinions, emotions, or attitudes Choosing the right statistic depends on: Type of measurement Nature of the comparison Number of groups to be compared EXHIBIT 15.1 Some Bivariate Hypotheses Cross-Tabulation Tables: The χ2 Test for Goodness-of-Fit交叉表：卡方检验拟合度 χ2 Test卡方检验 Provides a means for testing the statistical significance of a contingency table. Involves comparing observed frequencies (Oi) with expected frequencies (Ei) in each cell of the table. Captures the goodness- (or closeness-) of-fit of the observed distribution with the expected distribution.揭示观测到的分布与期望分布的拟合度 Chi-Square Test卡方检验 χ2 = chi-square statistic Oi = observed frequency in the ith cell Ei = expected frequency on the ith cell Ri = total observed frequency in the ith row Cj = total observed frequency in the jth column n = sample size Degrees of Freedom (d.f.) d.f.=(R-1)(C-1) Example: Papa John’s Restaurants Univariate Hypothesis:Papa John’s restaurants are more likely to be located in a stand-alone location or in a shopping center. Bivariate Hypothesis: Stand-alone locations are more likely to be profitable than are shopping center locations. Example: Papa John’s Restaurants (cont’d) In this example, χ2 = 22.16 with 1 d.f. The critical value at the 0.05 level with 1 d.f. is 3.84. Thus, we are 95 percent confident that the observed values do not equal the expected values. But are the deviations fro