Simple v simplistic: if McCandless reworked Minard:

There has been much interesting debate about David McCandless’ Information Is Beautiful this week, initiated by a well written critical piece by Stephen Few. I am pleased he has challenged the orthodox view that McCandless is the answer to the data visualisation industry’s problems.

On both FlowingData and Stephen’s own blog, there is debate about the difference between “simple” and “simplistic” graphics. This is a hard point to describe, and there are two comments on Stephen’s blog (by DR, and Stephen himself) that made me realise that a picture would emphasise the difference. I wondered how McCandless, if the accusation of simplicity is correct, would rework what’s often claimed to be one of the greatest data visualisations.

Consider the classic work by Charles Minard showing Napoleon’s disastrous 1812 march on Moscow. This graphic, I believe, fits Stephen’s definition of simple. Sure, there are many dimensions being displayed (soldier numbers, temperature, location, etc) but once the viewer understands that, the powerful anti-war message is unavoidable. The waste of life is brutally clear and well contextualised by the time location and temperature:

Minard's march on Moscow (from Wikipedia)#

(image from Wikipedia: http://en.wikipedia.org/wiki/File:Minard.png)

If McCandless is to be accused of simplicity, how might a simplistic version look? I think it would be like this:

Why? The simplistic approach tries to strip away as much data as it can. Minard’s main point was the loss of life. The version above shows just that and no more. One could argue that therefore it is more effective. But it isn’t. Minard’s simple graph gives much more context without any fluff and that, to me, is the difference between “simple” and “simplistic”.

Update: Fixed the spelling of David McCandless’ name – sorry about the typos

The journey is the destination

Unlike any other tool I’ve used before, Tableau invites exploration. One can start with a blank canvas and end up who knows where. That’s what makes Tableau fun to use. However strange that word looks when used in a work context, it’s true.

I had a challenge. I needed to produce a handout that compared survey data on two suppliers. We had twenty questions that were asked across 17 different functional areas by a bunch of people. That’s a lot of info.

Back in the old days, I’d have ended up with a gloriously dull pivot table made in Excel. It would have either summarised the data to death, ending up with a one page table that aggregated away any meaning. Or maybe I’d have produced pages and pages of charts that showed the trees but not the forest.

Instead, I connect the data to Tableau and go on a trip.The end results is the trellis above (click it to see the full size version). So why did this particular chart get me excited enough to write a post about it?

Was it because 2,194 marks are being displayed on one page? Partly.

Was it because every single question and answer can be viewed on one page? Sure.

Was it because you can look down a whole row or across a whole column and see exactly where one supplier outperformed another? Kinda.

Was it because it is very quickly clear that the supplier with the black line largely outperforms the grey supplier? Definitely.

Or was it because my client took one look at it and almost fell over because it was exactly what they wanted? For sure.

Actually, the main reason was more than just the above. It was the fact that when I connected to the data, I had no idea what my end result was going to be. I knew it was going to printed out, so had to find a way to keep the page count down. How did I design the trellis? I didn’t – I just had an inkling of what might work, dropped Dimensions and Measures around as seemed relevant, and the end result emerged almost on its own.

And that’s why Tableau works: you don’t need to know where you’re going, just set off and you’ll end up somewhere pretty damn cool.

3D pie charts in Tableau

Earlier today, I posted on the Tableau Forum, suggesting it would be great if Tableau did 3D pie charts. Well, I didn’t think it would be possible, but using some data pre-processing techniques, and hacking the preferences.tps, I’ve worked out a way of doing 3d pie charts in Tableau:

I knew those developers in Seattle would implement this fantastic visualisation technique eventually. Well done Tableau for letting the community take advantage of good quality graphics. I’ll explain how to do it in a subsequent post.

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