ABSTRACT
This chapter examines power for chi-square tests for independence (also known as multicategory, contingency) and Goodness of Fit (GoF; also known as one-way classification) address questions regarding distribution of scores into categories. The GoF test involves distributions for categories of a single variable whereas the test for independence examines whether membership in one category relates to membership in another (i.e., an interaction between variables). This chapter provides a detailed example using the test of independence and brief examples for GoF and 3 × 2 independence tests. The chapter also addresses tests involving comparing a proportion to a hypothesized proportion (one-sample test) and tests comparing two independent proportions. Finally, the chapter introduces power analysis using R through the pwr2ppl package.
