DLA claims – many eyes

IBM has their own free online visualisation platform called Many Eyes. It’s exceptionally easy to use – I put this together in maybe fifteen minutes. And it shows! Yeah, well done.

The data comes from the Department for Work and Pensions’ online tabulation tool. I’d been talking about Disability Living Allowance today for one reason or another so I thought I’d pull out some numbers. It’s a really easy to use resource for administrative benefits data, offering all the main benefits by a variety of different breakdowns. You do have to choose a breakdown, though, and gender is my go-to because it only gives you two columns and it generally won’t give zeroes. So if you want you can choose a breakdown for men or women and this adds a little interactivity and might be interesting.

What this is

What the diagram shows is the number of people claiming Disability Living Allowance by the diagnosis underpinning their main claim. There’s a split by men/ women at the bottom that can show you the gender dimensions, but they’re pretty similar.

Doing this

Like everything in the world you need to register at Many Eyes, click a link in an email etc and so on. Once done, though, you just need to drop a block of data from a spreadsheet into their little window and then it’ll start visualising.

What I decided to draw was this bubble diagram. I was only using numbers, counts, no proportions, so I thought this might be a good way of looking at them differently. If I didn’t have this gadget and was using Excel, I’d probably use a pie chart.

And the final result, barring a couple of text placing mishaps, looks pretty enough. But I’m not sure it’s a helpful presentation. One reason is because you can’t really tell the proportions of the circles. So arthritis is roughly twice the size of psychosis (563 cf 257) but there’s no obvious, visual way of figuring that out. That’s partly because the circles are arranged in a slightly haphazard manner so as to form a larger circle.

But mainly it’s because the eye, (by which we mean the brain, let’s be honest), has no idea how to compare the area of two circles. For one to be half the size of the other, the square root of one radius has to be half the square root of the other. There’s no way you can figure that out without a ruler.

But the main reason is that, even if you’re fine with the above (and you could well be, the numbers are there for you after all), you’ve got to do rather a lot of calculating to figure out what proportion of the whole any of the individual circles relate to. Here, the arthritis circle is about a fifth of the total. I know that because I’ve got the spreadsheet but because of the aforementioned eye/brain/ square root problems, you’d never figure that one out.

The thing is, the boring, default pie chart would solve both these problems. Granted, comparing slices of a circle isn’t that easy, but it’s much easier than comparing actual circles to each other. And the whole point of a pie chart is that it shows the parts of the whole by definition. All you need to know is what a half looks like, what a third looks like etc…and then at the very least you can have a good guess. Of course, if the pie slices are labelled, it’s loads easier.

Comments are closed.