Practical Data Analysis with JMP®

Two-Way ANOVA

Earlier we noted that our model accounted for relatively little of the variation in national birth rates, and that other factors might also play a role. To investigate the importance of a second categorical variable, we can extend our Analysis of Variance to include a second factor. The appropriate technique is called two-way ANOVA.

In some countries new mothers typically have lengthy maternity leaves from their jobs, while in others the usual practice is to offer much briefer time off from work. Let's use the variation in this aspect of prevailing national policies as an indication of a country's commitment to the well-being of women who give birth. We'll focus on the factor called MatLeave90+, a dichotomous variable indicating ...