There are a set of basic principles that hold true for the design of many graphs and various authors have their own preferences. One author who is prominent due to his good work in the area of data visualisation and presentation of evidence to support decision making is Edward Tufte.
Edward Tufte has proposed a set of design principles that should be kept in mind when evaluating the effectiveness of a visualisation method:
- Comparison: a graph should show comparisons and contrasts and highlight where differences occur.
- Causality: the data presentation should help the thought process in identifying reasonable explanations of cause and effect.
- Multivariate analysis: most data has more than one or two dimensions and these can be captured on a page of computer display.
- Integration of evidence: words, numbers, images and diagrams should be integrated into a single whole.
- Documentation: acknowledgement of data sources.