Selectable bubble chart
- Using area or volume to represent data can distort data values, and exaggerate differences between values. For example, if the radius of the circle is used to represent data values, the area of the circle will quadruple if the data values double. There is also an issue of 'perceptual scaling' - the tendency of people to underestimate areas.
- When using colours to portray data values or types, ensure that the colors used are accessible to all users. Online tools such as ColorBrewer (www.colorbrewer.org) can help identify issues with colours used.
- Bubble charts can be created in a range of standard data applications such as Excel.