YOUR ATTENTION PLEASE

Dick Pountain/PC Pro/Idealog 211 07/02/2012

My partner, along with thousands of others, received an iPad for Christmas this year. She's fairly computerphobic (though copes with her Windows XP netbook) and so she's pretty pleased with the device, and I'd have to say that I am too. The minimal user interface works very well, and the clean graphics put current Android-based competitors to shame. I'd like a hardware Back button like Android's, and a USB port would be nice too, but as a portable email client and e-book reader it's hard to beat.

What I've learnt from my iPad experience so far is the significance of its large form factor. I've used plenty of touch screens before - Palm Pilots right from the 1996 launch and an Android phone for more than year - and I've even written simple apps for both, but I've never until now used an A4-sized touch-only device for any length of time. It's a game changer. Size really does matter. The reason is simple physiology: a mobile phone's screen is small enough to fall wholly within your visual attention zone, but an A4-sized screen is more like a magazine or newspaper page where attention can only take in one section at a time. That makes design into a battle to direct attention. Now there's quite a lot known about this class of problem, and if you're planning to write apps for full-sized tablet computers you'd do well to acquaint yourself with this knowledge.

Obviously cognitive scientists have been studying the subject for years, driven by the needs of the aviation and automobile industries to accomodate more and more instruments into cockpit displays. They need to strike the right balance between grabbing immediate attention for high-priority alerts while retaining appropriate visibility for stuff you need to monitor continually. Equally obviously there's a huge reservoir of expertise in the graphic design profession, especially in the magazine and news trade. We get a head start in iPad app design thanks to our in-house art people, but all the tools of the trade from "White Out Box" to "News in Brief" will need tweaking to become suitable for the tablet screen.

You can stumble across further lessons in attention-seeking in the oddest of places. Last week's Guardian Food Blog featured an article entitled "The hidden messages in menus: Some restaurant menus can tell the diner as much about themselves as what's for dinner". The gist was that researchers at San Francisco State University recently overturned conventional wisdom about restaurant menu design, which was that diners start to read at the middle of the right-hand column, then jump to top left and read downwards. This belief has governed where restaurants position their special offers for years, and hence directly affects their turnover, but eye-movement sensors showed the SFSU team that it's not true - in fact diners read menus just like any book, down from top left and up again. This may cause a boom among US local print shops, to reprint billions of menus. The rest of the article describes how professional menu designers can manipulate diners emotionally, making certain options feel like bargains, while others provoke cheapskate guilt or flatter generosity.

I'm currently reading a fascinating book called "Thinking Fast and Slow" by a great guru of cognitive psychology, Daniel Kahneman, Princeton professor and Nobel laureate, in which he summarises a lifetime of study into the role of intuition in psychology. He's identified two independent thought mechanisms within the human brain. What he calls System 1 is intuitive, jumps to conclusions, is fast, amoral and fairly inaccurate: it's what saves us from hidden tigers and falling rocks. The other, System 2, is slower, deliberative, moral and responsible for self-restraint and future planning: it's who we think we are, though in fact System 1 is in charge most of the time. I already knew this because of my ability (which I'm sure I share with many others) to instantly re-find my place in a long text after taking a break - it only works if I *completely* trust where my eyes first fall, and if try to remember or think about it at all, it's lost. System 1 is also what makes me, temporarily, improve at darts or pool between my third and fourth pints. Kahneman's book is a goldmine of information about cognitive capabilities, delusions, illusions and misconceptions that ought to be a great help in UI design, given that System 1 is almost always in charge of such interactions.   

A Windows PC is pretty much a System 2 device, its plethora of menus, tabs and control panels forcing you to think about what you're doing for much of the time. I don't mind that but it appears that millions of people do, hence the success of the iPad. In effect Apple's device is a portable laboratory for cognitive science experiments, controlled entirely by gesture and sub-concious perception. I expect the revolution in UI design that it provoked to develop in quite unexpected directions over the next few years, which should put a lot of the fun back into computing. Will I be buying my own iPad? Perhaps not, but I can now afford to wait till Android tab vendors get it right (which may take some while, to judge by present form).