Unformatted text preview: of items Contingency Tables
Contingency Table: Two-way frequency table with row variable and column variable. Requirements: Random data of frequency counts and E Ú 5 for each cell (where E is expected frequency). Test of Independence: Test null hypothesis of no association between row variable and column variable. Test of Homogeneity: Test that different populations have same proportions of some characteristic. Test (independence or homogeneity) is right-tailed with test statistic: 1O - E22 x2 = a E where df = 1r - 121c - 12 Expected frequency (of cell): E= 1row total21column total2 1grand total2 Critical values for n > 30: rs = n1n + 1212n + 12 A 24 Statistically Stable Process (or within statistical control): Process with only natural variation and no patterns, cycles, or unusual points Out-of-Control Criteria: Two-Way ANOVA
Two-way ANOVA (analysis of variance) uses two factors: row factor and column factor. Requirements: Data in each cell are from a normally distributed population; populations have same...
View Full Document