ABSTRACT
In this chapter, the authors explore two-way between-groups analysis of variance (ANOVA). 'Two-way' means that there are two independent variables, and 'between-groups' indicates that different people are in each of the groups. This technique allows us to assess the individual and joint effects of two independent variables on one dependent variable. They used one-way between-groups ANOVA to compare the optimism scores for three age groups. They found a significant difference between the groups, with post-hoc tests indicating that the major difference was between the youngest and oldest groups. Older people reported higher levels of optimism. The main output from two-way ANOVA is a table labelled Tests of Between-Subjects Effects. This gives several pieces of information, not necessarily in the order in which the students need to check them.
