This post concerns tabular data rather than graphs. The design of a table is at least as important as the design of a graph, and in many ways there is a lot more that one can get wrong in a badly designed table.
The choice of whether to use a table or a graph shouldn’t be arbitrary. Stephen Few has pointed out that a table is usually a better choice than a graph to communicate MI when:
- The display will be used to look up individual values
- It will be used to compare pairs of values but not entire sets of values to one another
- Precise values are required
- The quantitative information to be communicated involves more than one unit of measure
- Both summary and detail values are included
Nigel Holmes, the renowned pioneer of infographics design, wrote: “Tables work especially well when numbers differ by orders of magnitude so that no scale suffices in plotting them. Consider this set of numbers: 20; 400; 160,000; and 25,600,000,000. A chart will lose the detail of low figures if it tries to reach the high ones without breaking the scale. If you must break the scale, then just use a table, because a chart with a broken scale is no longer a true picture of the numbers.”
And the visualization guru Edward Tufte said “Tables usually outperform graphs in reporting on small sets of 20 numbers or less.”
Designing tables that do their job effectively is a science as well as an art. Future posts on this blog will look at aspects of good table design.