“A little light reading, hey?” the doctor from Pennsylvania asked me on a recent flight. “Do you have to read that for a course or something?”
“No,” I said as I showed him a fascinating chart of Napoleon’s army’s advance to and retreat from Russia, “I’m actually just reading it for fun.”
And despite the fact that the cover looks like required reading for a 1960’s advanced course in Macroeconomics, it WAS fun.
Even the cover is fascinating. The graph on it looks like a meaningless jumble of lines, but it actually contains the entire train schedule of France from 1885. It is so rich in information and so elegant. It’s a thing of beauty.
The book goes on to highlight many amazing graphs, as well as a few counter-examples, and explains what makes them good or bad.
It all boils down to just a few principles. The ones that stuck with me were:
- Don’t waste “ink” on unnecessary or distracting “chartjunk”,
- don’t use a chart when a table will do, and
- don’t lie.
An example of wasted ink included using internal grid lines, which often reduce the readability of the actual data. This should be avoided.
As for using charts vs. tables, the “magic number” that Tufte gave was 20. If there are fewer than 20 pieces of data, it’s often better to print those values directly in a table than for to abstract them into a chart.
The book contained several examples of charts that lie. The biggest offense was shifting axes for some or all of the data in a chart to make the data seem better or worse than it actually is. Tufte also recommended adjusting monetary values for inflation whenever possible.
Applying these ideas
I work as a UX designer for Solium, an equity compensation software company. What does that mean in English? Many companies reward their employees by giving them ownership through things like stock options and savings plans. Solium makes software that helps those companies keep track of these plans.
We recently released a redesigned interface for these employees (participants). These participants have appreciated the new interface, though there are still a few important questions that it doesn’t fully answer for them. One of which is “When am I going to get my money?” because these equity compensation programs usually have what’s called vesting, where rewards are only released after the recipient has worked for the company for a certain amount of time, usually 1-4 years.
I’m now working on a simple, compact, easy-to-learn chart that shows the vesting schedule for a participant. It may never end up being released in our software, but it’s definitely been a fun exercise exploring different concepts based on what Tufte taught me!
For details on these charts, see Visualizing vesting schedules.
Definitely worth a read!
Anyway, The Visual Design of Quantitative Information was a great read. I’d definitely recommend it if you work with data or are curious about how these things work… Or if you want to impress that doctor sitting next to you on a flight.