A bar graph can be used to visualize differences in mean scores across categorical conditions. For example, a bar graph can display the mean clinician rating of severity for three different experimental groups: an Education condition, an Exposure condition, and a Control condition. The categorical conditions are plotted on the horizontal axis, and the quantitative severity ratings are plotted on the vertical axis. The data shows that the Control condition resulted in the highest severity rating ($5.56$), compared to the Education ($4.83$) and Exposure ($3.47$) conditions.