ABSTRACT
This chapter presents detailed explanations of several measures of strength of association (correlations) and one test of significance appropriate for contingency tables with nominal and ordinal variables. Students sometimes wonder whether it is practical to learn how actually to compute such measures; after all, computer programs are almost always used for the task. There are two reasons why it is useful to have some familiarity with methods of computation. One is that you may occasionally find yourself looking at a simple frequency table for which it might be quicker simply to compute a statistic by hand than to enter the data into a computer. The more important reason, however, is that knowledge of how a statistic is defined and computed provides a deeper understanding of its meaning, which is valuable in understanding how to apply and interpret it correctly.
