Compound Bar Chart

A bar chart where the categories are stacked on top of each other. This allows for the visualisation of the proportion of each category each represents. Usually used when comparing two or more sets of data. A key is needed to interpret the data.

Dual Bar Chart

A bar chart where each category has two bars instead of one. This is used when two frequencies exist for a category. This type of graph allows for comparisons to be made between the two sets of values.