Information visualization: frequently asked questions

New to information visualization? Let me give you some quick answers to frequently asked questions.

What is a chart?

Just open your eyes and an amazing amount of data is immediately funneled into your brain. This data is processed in real time and makes possible your interaction with the outside world. Shapes and patterns emerge and you’ll be able to tell a tree from a building.

A chart is a device that takes advantage of this power by plotting abstract data in space. Since similar data points will be plotted next to each other, you’ll see some patterns that would be very difficult to uncover just by looking at the data itself. When you are creating a chart your primary concern should be to simplify that pattern discovery. Everything else is wrong. Everything else is marketing.

Why should I use charts?

Because data is expensive and you should get the most out of it. Because charts allow you to process data efficiently. Because you get insights that you wouldn’t get using other methods. Because they save time.

How to I create professional-looking charts?

Don’t use the charts you see in magazines as a model, if that’s what you mean be “professional-looking charts”. Usually they are more form than function, eye-catching but irrelevant. If you are using charts to support a decision making process just make them clean, and let them tell their story.

But my manager loves flying 3D pie slices in PowerPoint…

I am a terrible player at impression management but I know this can be a problem. Play by the rules and you’ll be on the safe side (or not). Play against them and you’ll either be promoted or fired…

If you want to change the corporate culture regarding information visualization use visualization to do it. People usually are not stupid, they just don’t have the right information. Evangelize. Make them compare current practices with the ones you are promoting and let them judge the real benefits. If they are obvious people will see them. Be patient and persistent. People change. Slowly.

What tools should I use?

If you work in a corporate environment probably you can’t avoid Microsoft Excel, or other spreadsheet application (Powerpoint should be available also but you better avoid it). Don’t use defaults, keep away from some stupid options and Excel can really be a good starting point.

If you are more design oriented, you could use Illustrator or a good mixture of design and a programming language like Processing. Keep the programming language, remove the design and add statistical packages and you get SAS or R. Use Spotfire for interactive analysis of large datasets.

Give me a single tip to make better charts today

Make them smaller.

What?!

A smaller chart forces you to remove all the junk you once thought was essential (just like starting to live on a tight budget…). Then add more charts to that empty space and you end up with a more detailed picture of your data. Small charts are beautiful.

What about authors and books?

No book had more influence in the way we think about information visualization than Edward Tufte’s The Visual Display of Quantitative Information (Tufte’s books are a pleasure for the eyes so you can leave them in the living room…). Tufte combines a minimalistic approach with easily digestible concepts (like chartjunk, data-ink ratio, data density) to create a strong framework. Use that framework to validate your design. Discover other authors like Stephen Few, Jacques Bertin, William Cleveland, John Tukey, Stephen Kosslyn or Colin Ware.

What online resources are available?

Edward Tufte maintains a discussion forum. In Stephen Few’s site you’ll also find a discussion forum and some before/after examples of chart design. It is difficult to find great examples of information visualization in the media, but the NYT is a good reference. A list of online resources can be found here.

I’ll answer your questions…

… if I know the answers. Leave them in the comments.