Numeracy Skills

3. Reading & Interpreting Graphs and Charts

3.1. Bar Charts

Bar charts (also known as bar graphs) present data in the form of either vertical or horizontal columns.

The x axis (horizontal) of the chart represents the type of data we are dealing with and the y axis (vertical) assigns a value (number/amount) to it.

Translating the information from the grid on the previous page generates the following graph:

bar chart

Bar charts offer an effective method for comparing two or more sets of data, especially when these have been compiled over a given period of time (a weakness, as we shall see, of pie charts). They generate a visual depiction which can reveal patterns and trends in numerical data, particularly in tabular form.