EXAMPLE 30 Careless combination of categories in a bar graph and biased embellishment

Figure 60 shows a bar graph of how often people have observed drivers running red lights. Explain how this bar graph may be considered both confusing and biased.

Solution

One problem with this bar graph is that the categories of seldom and never have been combined, which may not be appropriate. Also, as we learned in Chapter 1, what is “seldom” to one person may not be “seldom” to someone else. A third problem is that the bar of the Seldom/never category is highlighted in a different color, which may be evidence of bias on the part of the designer of the bar graph.