Bar graphs and pie charts are two popular ways to graph the distribution of nominal and ordinal variables. Figure 20.1 shows bar graphs for two of the variables in table 20.2: GENDER and GUNGHO. Figure 20.2 shows the pie charts for the same variables. Notice that in the bar charts, the bars don’t touch one another. This indicates that the data are nominal or ordinal and not continuous.

FIGURE 20.1.

Bar charts for the variables GENDER and GUNGHO in table 20.2.

The categories of the variables are shown along the horizontal axis of the bar graph. The horizontal, or x-axis, is also called the abscissa. The number of each category is shown on the left vertical axis. The vertical, or y-axis, is also called the ordinate. You can show the percent of each category on the y-axis instead.

In figure 20.1a, men are labeled 1 and women are labeled 2. Notice that it makes no

FIGURE 20.2.

Pie charts for the variables GENDER and GUNGHO in table 20.2.

difference whether we put the bar for men or the bar for the women on the left or the right when we graph GENDER. There is no order implied in the attributes of a nominal variable. When we graph ordinal variables, however, like GUNGHO, the order of the bars becomes important.