22-bivariate stats.ppt

Exploring Marketing ResearchWilliam G. Zikmund
Chapter 22:
Bivariate Statistics-
Tests of Differences
Copyright © 2000 by Harcourt, Inc.
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Common Bivariate Tests
Type of Measurement
Differences between
two independent groups
Differences among
three or more
independent groups
Interval and ratio
Independent groups:
t-test or Z-test
One-way
ANOVA
Type of Measurement
Differences between
two independent groups
Differences among
three or more
independent groups
Ordinal
Mann-Whitney U-test
Wilcoxon test
Kruskal-Wallis test
Common Bivariate Tests
Type of Measurement
Differences between
two independent groups
Differences among
three or more
independent groups
Nominal
Z-test (two proportions)
Chi-square test
Chi-square tst
Common Bivariate Tests
Type of
Measurement
Differences between
two independent groups
Nominal
Chi-square test
Differences Between Groups
Contingency Tables
Cross-Tabulation
Chi-Square allows testing for significant differences between groups
“Goodness of Fit”
Chi-Square Test
x² = chi-square statistics
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
Chi-Square Test
.=(R-1)(C-1)
Copyright © 2000 by Harcourt, Inc. All rights reserved.
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