16. Design and sample size decisions

16.1 The problem with statistical power

16.2 General principles of design, as illustrated by estimates of proportions

16.3 Sample size and design calculations for continuous outcomes

16.4 Interactions are harder to estimate than main effects

16.5 Design calculations after the data have been collected

16.6 Design analysis using fake-data simulation

16.7 Bibliographic note

16.8 Exercises