“…Of all methods for analyzing and communicating statistical information, well designed data graphics are usually the simplest and at the same time the most powerful…”

Graphical displays should:
– Show the data
– Induce the viewer to think about the substance rather than about methadology, graphic design, the technology of graphic production or something else
– Avoid distorting what the data have to say
– present many numbers in a small space
– Make large data sets coherent
– Encouage the eye to compare different pieces of data
– Reveal the data at several levels of detail, from a broad overview to the fine structure
– Serve a reasonably clear purpose: description, exploration, tabulation, or decoration
– Be closely integrated with the statistical and verbal description of the data set

“Why waste the power of data graphics on simple linear changes, which can usually be better summarized in one or two numbers? Instead graphics should be reserved for the richer, more complex, more difficult statistical material.”