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As we discussed in the previous section, bar graphs are used to display categorical (i.e., nominal) data. For example, suppose we want to know which group of students, first-years or seniors, scored higher on the measure of burnout. To find out, we can make a bar graph with the variable of year in school on the x-axis and average burnout score on the y-axis. As you can see in Figure 3.5, seniors did have a higher score on the burnout measure than did first-year students. In Chapters 7 and 8, we will learn to use tools that will allow us to determine whether in fact this is a meaningful difference between the two groups of students.

Figure 3.5 Using a Bar Graph to Display Average Burnout Scores for First-Year and Senior College Students in Wendt’s (2013) Research

Let’s examine another example of a bar graph. In a research study that we will detail in more depth in Chapter 10, Donte Bernard and his colleagues (Bernard, McManus, & Saucier, 2014) asked students to allocate a fixed amount of money to various campus student organizations. Some of their results are displayed in a bar graph that you can see in Figure 3.6. Along the x-axis is the name of each student organization. The y-axis contains the average amount of money that participants allocated to each organization. Again, notice that there is a space between each bar because student organization is a nominal variable.