Using Charts Effectively

There are seven basic types of charts and each has a unique purpose:

• Pie chart – for illustrating a proportional relationship between a segment and a whole.

• Bar Graph – for comparing the size or magnitude of a group of items; these can be vertical or horizontal, and can also be clustered or stacked to show differences between samples. 

• Histogram – for comparing the distribution of a set of data across a scale (e.g. time, elevation, monetary value).

• Line chart – for plotting a trend in data.

• Area chart – for comparing changes in quantities over time.

• Dot chart (or scatter plot) – for showing whether a relationship between two variables follows an expected pattern. 

• Gantt Chart or Timeline – for communicating incremental data, usually related to time/duration, or showing the relationship of events to each other across a time scale.