Another approach to representing frequency data is the frequency histogram, which graphs frequencies as bars. This type of graph is called a bar graph when the underlying variable being graphed is non-continuous. For non-continuous or discrete variables (e.g., gender), the bars that are drawn don’t touch. For continuous variables (e.g., weight), they do touch. In general, the scores are plotted on the abscissa (the horizontal axis) and the frequencies on the ordinate (the vertical axis). The width of the bars represents the intervals, and the height of the bars represents the frequency of scores in each interval. Figure 1 is a frequency histogram of the exam scores in the ungrouped frequency distribution presented in Table 1.