Chapter 4: Two-Way Contingency Tables
SummaryThe analysis of two-way frequency tables concerns the association between two variables. A variety of specialized graphical displays help us to visualize the pattern of association, using area of some region to represent the frequency in a cell. Some of these methods are focused on visualizing an odds ratio (for 2 x 2 tables), or the general pattern of association, or the agreement between row and column categories in square tables.
- 4.1. Introduction
- 4.2. Tests of association for two-way tables
- 4.3. Stratified analysis
- 4.4. Fourfold display for 2 x 2 tables
- 4.5. Sieve diagrams
- 4.6. Association plots
- 4.7. Observer agreement
- 4.8. Trilinear plots
- 4.9. Chapter summary
- 4.10. Lab exercises
Selected figuresview R code
Figure 4.2Spineplot of the Mental data.
Figure 4.2Fourfold displays for the Berkeley admission data. Left: unstandardized; right: equating the proportions of males and females.
Figure 4.9Sieve diagrams for the HairEyeColor data. Left: expected frequencies shown in cells as numbers and the number of boxes; right: observed frequencies shown in cells.
Figure 4.17Association plot for the hair-color eye-color data. Left: marginal table, collapsed over gender; right: full table.
Figure 4.18Agreement charts for husbands’ and wives’ sexual fun. Left: unweighted chart, showing only exact agreement; right: weighted chart, using weight w1 = 8/9 for a one-step disagreement.
Figure 4.20Weighted agreement charts for both patient samples in the MSPatients data. Departure of the middle rectangles from the diagonal indicates lack of marginal homogeneity.
Figure 4.22Lifeboats on the
Titanic, showing the composition of each boat. Boats with more than 10% male passengers are labeled.