Jack Schofield from the Guardian has his nether garments in a twist about a pie chart in Steve Jobs’ most recent keynote. Here’s the chart:

[Image credit – Endgadget]

Schofeld’s beef is that the 19.5% market share slice for Apple’s iPhone somehow looks bigger than the 21.2% market share for the mish-mash of “Other” brands. Now, to be fair, this is a common problem when you present data using any kind of 3-D effect, and it is for that reason that I usually recommend my clients to minimise use of those effects. They are particularly annoying / misleading on bar charts on which you frequently can’t tell where on the Y axis a particular value falls.

But Schofield goes overboard in his piece [slow news day maybe?] when he suggests that it is inappropriate to list the brands out of order this way – suggesting that the chart should show RIM, then Others, then Apple.

Twaddle Jack! Moses presented “All other brands” as the final, and least important, slice of his etched-on-sandstone pie charts. Who is beside “Other” on this chart? Nokia, with 3.1%. That tells me that the “Other” comprises a bunch of brands that have 3% market share or less. They’re nonentities. They are irrelevant to the point this presenter is making, which is that his brand has captured a fifth of the market in less than 12 months, leaving major players in the US market gasping.

Now, as to the larger point of a presenter inflating his credibility by skewing the perspective on a pie chart like this, I sort-of agree. If the chart was presented like this:

… then I would say that Mr Jobs was deliberately looking to skew the world’s view on just how successful the iPhone has been. But he presented it with the data values in the slices. I don’t know about your left brain, but my left brain tells me that 21.2% is bigger than 19.5%, and my right brain can quickly perceive the highlighting and shadowing effect on the bottom of the Pie Chart to tell me that this is an away-leaning Pie.

Du-uh!

Would Jobs have been better to show this as a flat chart? Possibly, but it would have looked out of place in the rich 3-D environment we have come to expect from an Apple keynote. What will be very interesting will be if he does something like this again …

Les Posen’s comment on this on the Wired blog is worth re-thingying [well it isn’t re-printing, and re-blogging just sounds silly, so what is it?]:

“I’ll use this article (and its comments section) in my workshop on Presentation Skills using Slideware, in the afternoon section on Information Visualization, subsection: data distortion – how to use it to your advantage (but only once lest you lose audience trust trying it a second time). Or: the importance of colour and placement of data you want your audience to most attend to …” [Posted by: Les Posen | Feb 7, 2008 3:16:17 PM]

Very well said Les. We all seek to “lead the audience by the nose to the thought” in our presentations and colour and placement on the slide are two very important elements in that mix. As to the distortion accusation; in my experience that is a technique used to cover one’s rear end following a failed effort in the market, not as game-playing to exaggerate a sterling success.

I read years ago that Adolf Hitler had a world map up on his wall, with Germany placed at the centre, which gave a distorted sense of Germany’s relative size (courtesy of Herr Haushofer). I somehow doubt that Mr Jobs is similarly unglued in his worldview …

Schofield’s rant is here [including a bizarro-world tangential rant about smartphone operating systems. He really was cranky that day – cold porridge maybe?]

Wired waste a bunch of pixels doing a breakdown on the perspective element in the pie-chart. [H/T Peter]