The Truthful Art: Data, Charts, and Maps for Communication

5. Basic Principles of Visualization

In the course of executing that design, it occurred to me that tables are by no means a good form for conveying such information.... Making an appeal to the eye when proportion and magnitude are concerned is the best and readiest method of conveying a distinct idea.

—William Playfair, The Statistical Breviary

There is a time in every class and workshop when someone raises her hand and asks: How do you know that you have chosen the right graphic form to represent your data? When is it appropriate to use a bar chart, a line chart, a data map, or a flow diagram? Geez, if I had the answer to that, I’d be rich by now. I invariably reply, “I have no idea, but I can give you some clues to make your own choices based ...