Pie charts with more than five or six slices should be avoided. For this reason, pie charts are used only with categorical data with a relatively small number of values or categories. Use a bar chart when you are showing several categories. Bar Chart Bars are often used to compare differences between groups. This type of chart, like the pie chart, is also used with categorical data, and can illustrate up to about 15 categories very effectively.
Bar charts make small differences between categories easily distinguishable.
The scatter plot can easily show hundreds of data points. In fact, the scatter plot is often used to discern or illustrate patterns in a large data set. Next For Further Reading Morris, Lynn Lyons, Carol Taylor Fitz-Gibbon and Marie E. Freeman. How to Communicate Evaluation Findings . Links contained in this file to information provided by other organizations are presented as a service and neither constitute nor imply endorsement or warranty.