Thinking about the reasons and theory of data visualization

Quoting Edward Tufte in the Introduction of The Visual Display of Quantitative Information

Data graphics visually display measured quantities by means of the combined use of points, lines, a coordinate system, numbers, symbols, words, shading, and color ... Modern data graphics can do much more than simply substitute for small statistical tables. At their best, graphics are instruments for reasoning about quantitative information. Often the most effective way to describe, explore and summarize a set of numbers - even a very large set - is to look at pictures of those numbers. Furthermore, of all methods for analyzing and communicating statistical information, well-designed graphics are usually the simplest and at the same time the most powerful.

With that in mind, let's together consider how one can display data in chart form

Visualization of data has a long history, but the addition of more powerful computing and newer programs has given us the opportunity to display data in ways that are enlightening.

The tool, however can be misused, either by intent or by ignorance

How to Lie with Statistics and The Best and Worst of Statistical Graphics by Michael Friendly at York University, Canada


Some names to know

Jacques Bertin and his classic book, The Semiology of Graphics

Edward Tufte and his three classics


Some additional thoughts on data display

Data can be displayed in good and bad ways

Scholars at York University in Canada have put together a useful gallery of good methods of display and also of ideas to avoid

You have a lot of good examples to study for inspiration and emulation.


Does it matter?

Lessons for data analysts from the Challenger disaster tells us good data display could be a life or death issue.

But there are always several different ways to view the same situation and not everyone agrees with Tufte.

Let's re-iterate our points again.

Dilbert cartoon from 07 March 2009