From time to time, Seth Godin comes to visit our little field of information visualization, and I’m pleased to note that he is learning…
Today’s post, “How to make graphs that work” is remarkably better than “The three laws of great graphs” or “How to make a PowerPoint chart”. Today he warns us against Excel and PowerPoint defaults and templates, invites us to tell a story, by following some simple rules and braking some other rules. It’s clearly a post on the safer side…
But I do have some remarks. Godin says:
when you show me something exactly like something I’ve seen a hundred times before, what do you expect me to do? Here’s a hint: Zzzzzz.
Right. That’s the problem with defaults and templates. But it’s a problem with all defaults and templates, no matter how good they are. So, what can you do? First choice: be relentlessly creative. Can you do it? Good for you, I can’t. Second choice: make your charts invisible. Show the message, not the chart.
Pie charts are spectacularly overrated. If you want to show me that four out of five dentists prefer Trident and that we need to target the fifth one, show me a picture of 5 dentists, but make one of them stand out. I’ll remember that.
I actually prefer the Presentation Zen style. If you have two slices, you just need a percentage. And be careful with the pictures you choose. In this case, I see a female dentist that doesn’t prefer Trident on Wednesdays…
You can animate, but only if you have a note from your doctor.
You can animate if there is a pattern inside (Hans Rosling, anyone?).
So, what do you think? Is Seth Goding ready for serious information visualization?
Seth’s blog is always interesting, and usually I agree with him and learn something. However, when he discusses charts and graphs he’s often a very light purple cow. This week he confirms that.
Godin’s The three laws of great graphs tells us that, when using graphs in presentations, we should follow these simple principles: “one story”, “no bar chars” and “motion”. Strange laws: a story with no substance, a caricature and motion without motion.
One Story per chart? No, one story per slide
“No, the reason you put a chart in a presentation is to tell a story. A single story, one story per chart. (…) There is no room for nuance here.”
Hmmm… story, no nuance. OK. But if a chart can only say “boy meets girl” isn’t there something missing?
A slide can be seen as an information unit (an “information chunk“) – that’s why Tufte writes about arranging things “adjacent in space rather than stacked in time”. It is the slide that tells the story, not the chart or any other single object. Actually, the presentation is your story – a slide is just a paragraph, a chart is just a sentence.
I can accept the idea of a nuance-free slide, but that doesn’t equal to an information-poor slide.
No bar charts – A caricature
Godin tells us that bar charts are overrated, and they should be replaced by a line/area chart (change over time) or a pie chart (comparing items at the same scale). You should use bar chart for before/after comparisons only.
I absolutely agree with Godin, you should never use bar charts – if your idea of a bar chart is similar to the one displayed in his post.
A nuance-free slide content is one thing, but different tools convey different messages, and you should be aware of those nuances. Time series 101: use bar charts to compare data points, use line charts to display trends. Categories 101: use pie charts to show proportions, use bar charts to rank data points.
Motion without motion
What Godin calls “motion” is just a silly dramatic effect for presentation purposes. “Look how fat I was”, and boom! “look how many pounds I’ve lost!” (fireworks and John Williams soundtrack). Motion can play a relevant role in presentations, but this is no motion, like a fake 3D chart is just a fake.
Bar graphs vs. pie charts
For whatever reasons, Godin decided to take a stance against bar charts. That’s ok, but his arguments are unfair (just look at the examples he uses in both blog posts). Let’s change the data in his second post and add meaningful trends to the time series:
“Trolls are where we should focus our energy.” Are you sure? In his bar chart example there is no trend, no visible pattern. “There’s data here, but no information.” Well, just remove the unnecessary data. By the way, if the slices in a pie chart are labeled you don’t need a legend…
Do you really want three laws of great graphs? Here they are:
- Tell a story;
- Remove irrelevant data;
- Choose the right messenger;
- Bonus law: let the user write the story.
[Update: several "data presentation purists" are discussing this:
