Seth Godin, well-known marketing guru, took a strong and misguided stand against bar charts¹ in a recent blog post entitled “The three laws of great graphs”

Godin suggests that bar charts (and presumably other chart types like scatterplots, bubble charts, bullet charts, treemaps, etc.) give too much latitude for data confusion and ambiguity when used in presentations. In Godin’s view, a chart should make a single, clear point and leave no room for alternative conclusions.

“The only reason (did I mention only) to use a chart in a presentation is to make a point. If you want to prove some deep insight or give people textured data to draw their own conclusions, DON’T put it in a presentation.” “If the facts demand nuance, don’t use a graph, because you won’t get nuance, you’ll get confusion.”

Godin had hit on a similar point a while back when he critiqued Edward Tufte’s favorite infographic Napoleon’s March to Moscow.

“I think [Tufte] is completely out of his gourd and totally wrong. I think this is one of the worst graphs ever made…To make me take 15 minutes to study it doesn’t make sense.”

I agree that complex infographics aren’t an effective communication mechanism for many audiences, particularly if you are interested in telling a focused story.

Unfortunately, he uses this reasonable foundation as a jumping off point to claim that bar charts are overrated and unnecessary (he throws in a heinous 3D column chart for emphasis). “The problem with bar charts,” he says “is that they should either be line/area charts (when graphing a change over time, like unemployment rates) or they should be a simple pie chart”

That popping sound you hear is Stephen Few’s head bursting.

It is reasonable to argue that a value changing over time is often better suited to a line or area chart. But pie better than bar. Sorry, no can buy. He obviously got some flak after this first post:

“I stepped on the toes of many data presentation purists² yesterday, so let me reiterate my point to make it crystal clear: In a presentation to non-scientists (or to bored scientists), the purpose of a chart or graph is to make one point, vividly. Tell a story and move on. If you can’t be both vivid and truthful, it doesn’t belong in your presentation.”

His follow-up post Bar graphs vs. Pie charts attempts to solidify his argument but ends up stepping in more goo. To make his point, he shows a effective pie chart versus an ineffective bar chart.

In a not so subtle sleight of hand, he has added another data series to the bar chart to show how it doesn’t make a single, clear point. As my colleague Pete likes to say, if my aunt had…

His argument appears to boil down to a belief that pie charts are so simple that it is impossible to deviate from his one-point-per-chart rule. Or put another way: presenters can’t be trusted to follow this rule, so best to take away anything dangerous. This parallels the misplaced anger people have toward PowerPoint. I wrote a post called A Poor Craftsman Blames His Tools.

That question aside, I reject his rejection of bar charts for a number of reasons:

• There is a lot of evidence that bar charts are superior to pie charts even when showing simple data. Bar charts allow for better labeling and show relative size more effectively.
• Pie charts are the most frequently mis-used charts in my experience. There seems to be an irresistible need to craft animated, 3D, shiny pies — all of which adds zero communication value.
• Restricting data presentation to a few chart types limits your ability to communicate. Scatterplots, for example, can carry powerful and clear messages about relationships between variables.
• If the data and message is super simple (as Godin would want), using a chart is likely a waste of pixels. In his pie chart above, the only message he wants to convey is that trolls rule. Why not simply state: “Trolls are the largest segment with 45% share” and leave out the chart.
• Bar charts can show trends and magnitudes simultaneously. I don’t believe this has to be a liability in communication, nor should they always be separated. If I wanted to show that trolls are both the biggest segment and the fastest growing, breaking those facts into separate slides seems more distracting than useful. The points are tightly linked and supportive of each other.

1. The “bar” chart that Godin refers to is actually a column chart. I’ll use the term bar charts to refer to both bar and column charts in this post. However, the distinction between these two chart types is important as each chart is appropriate in different circumstances. For example, when there are a lot of categories, a (true) bar chart allows for much clearer labeling.

2. “Purists” seems to be used to label the objectors as a bunch of academics who don’t appreciate the realities of the business world. If you’re a loyal reader of our blog, you know that is a stick we prefer to use on others.

One area we’ve been paying particular attention to recently has been the internet traffic for different web site categories. Our friends over at comScore Inc. collect a wealth of information for “measurement of the myriad ways in which the Internet is used and the wide variety of activities that are occurring online.” Nice alliteration, guys.

Using some of the data they’ve allowed us to share with you, we had the bright idea to stuff it into our most favoritest charting type, the treemap. And what’s better than a chart? Answer: an interactive chart with a toggle button.

You’ll need to know a few things to really Juice the data:

• The map is based on unique visitors by site for August 2007 and November 2007.
• Red means a decrease in unique visitors over that three month time period and green means an increase. Black means there is no change.
• You can click on the category headers to zoom into each category. Click on the category header again to zoom back out.
• We provide two views of the data: the default shows just the top ten sites in each category. However, for nearly all categories, sites outside the top 10 account for over 50% of the visitation in the category (the exceptions were Search, Portals, and Auctions where the top players dominate traffic). A checkbox adds “All Others” and gives you a better sense of the size of each category. You can toggle these two views using the checkbox just below the map.
• Due to some confidentiality restrictions that we’re under regarding the raw data, we couldn’t show other metrics that would really make this visualization sing—but I bet if you contacted comScore, they’d be glad to discuss with you.
• A few tech notes. The treemap is adapted from Josh Tynjala’s capable open-source Flex Treemap component. Site images are provided by Amazon.com’s Alexa site thumbnail service.

So, without further ado, take a gander at our latest liberated data:

http://internetmap.juiceanalytics.com/

There’s so much information here, you won’t have any trouble drawing your own conclusions, but here are a few conversation starters:

• Notice that there was a distinct increase in retail web visitors leading up to the holiday seasons.
• Surprise! eBay owns auctions
• Not too good of a showing for those online gambling sites; travel either.
• Sports traffic is up… but not for the MLB.com site. Oh yeah, baseball season is over.

Enjoy.

Disclosure: comScore is a client of Juice Inc.

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Edward Tufte has produced a illuminating video tour of the user interface of the iPhone. The video illustrates Tufte’s struggles to come to grips with the difference between dynamic screen resolution and the resolution of printed paper. Tufte is prone to grandiose pronouncements, like this one:

All history of improvements in human communication is written in terms of improvements in resolution: to produce, for viewers of evidence, more bits per unit time, and more bits per unit area. Slideware is contrary to that history. Trading in reductions in resolution for user convenience or for pitching may be useful in mass market products or in commercial art, but not for technical communications. The solution is not to rescue slideware design; the solution is to use a different, better, and content-driven presentation method. On this solution, see our thread PowerPoint Does Rocket Science—and Better Techniques for Technical Reports — Tufte Nov 10 2006

Somehow, I don’t think the importance of the Gutenberg Bible related to it showing “more bits per unit area.” Quick, count the “bits per unit area.”

It didn’t take bits per unit area to revolutionize communication in the past and it won’t in the future either. The iPhone is a tremendously engaging information device and points the way forward for information displays. Here’s what the iPhone does well:

Maximize screen real estate: Controls are only visible when needed, fading away gently when you are concentrating on content. Tufte furiously neologizes, calling this “computer information debris.” Control junk is more apt, more terse, more Tuftian.

Direct manipulation: As Tufte says: information is the interface. Filtering and choosing should take place in the context of direct manipulation. A good essay on the possibilities of direct manipulation can be found here.

Fun: Above all, information can be fun and engaging to navigate. Tufte condemns Apple’s stock ticker for having “cartoony” and PowerPoint-like displays and offers an improved version (with 5 digits of precision). Apple’s cheery display offers a more entertaining, usable interface for day-to-day usage.

With our empathy for the day-to-day troubles of the business person seeking insight in data, it’s frustrating listening to Tufte. He is clearly an academic, with academic interests and academic timeframes. As much as his work is respected and inspirational within business circles, he makes little effort to enable his message to be implemented.

Good Tufte: Clutter and overload are not an attribute of information, they are failures of design. If the information is in chaos, don’t start throwing out information, instead fix the design.

Bad Tufte: “…the conclusion of sparkline analysis in Beautiful Evidence, where the idea is to make our data graphics at least operate at the resolution of good typography (say 2400 dpi).” http://www.edwardtufte.com/bboard/q-and-a-fetch-msg?msgid=0002NC&topicid=1 *Ed: At least 2400 dpi? Orly?

Mostly right Tufte: “Thus the iPhone got it mostly right.”

Mostly wrong Tufte: “Adobe Illustrator is a big serious program that can do almost anything on the visual field (other than Photoshop an image). Most of my sparkline work was done in Illustrator. Fortunately all graphic designers and graphic design students have the program and know how to use it, so find a colleague who knows about graphic design.” http://www.edwardtufte.com/bboard/q-and-a-fetch-msg?msgid=0000Jr&topicid=1&topic=Ask%20E%2eT%2e

It is heartening to see Tufte engage and connect his mental frameworks to our modern, screen-oriented, graphics-accelerated, not graphics-designed world. But the future of information design and interaction belongs to the iPhone, not the printed page.

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