Friday, 13 February 2015

Tapping, swiping and consistency in the language of user experience

I bang on about the language of UX. Most people refer to it as 'conventions' but for me, it's a language. The motions and interactions that a user has with a device to execute commands is a language, in the same way that we talk of programming languages.

Languages, of course, evolve. The same is true of UX languages. New commands come into play as the operating systems gain new functionality. For example, on a phone, tapping a picture magnifies it to fill the screen. This is true whether you're looking at socks on eBay, fish on Facebook or houses on Rightmove. Likewise, Twitter. It's the equivalent of a green light on your traffic lights. It's a universally applied command. If your spouse says, "Take out the rubbish!", you don't load the washing machine.

But closing a picture hasn't had a universally applied language. Historically, coming from the world of non-touch PC screens, a little cross in the corner of a picture was a prompt to close it. Actually, some people didn't know that and Facebook, for example, changed the little cross to a 'Done' button. But this is the world of touch screens, where physical interactions - taps, swipes, shakes etc - are prevalent and intuitive. Intuitive, that is, until one service breaches the rules of the language. And Twitter was the culprit.

A little like saying "I went for a run tomorrow", meaning "I will go...", Twitter was - as far as I know - the only service that used tap both to open and to close a picture. Facebook and the rest followed a different rule: tap to open, swipe down (or up) to close. Once open, tapping enabled the user to show or hide text overlay or written commands.

Yesterday, it seems, Twitter came into line. Tap open, swipe closed.

Why does this matter? Because if we go back to the question of "eliminating distraction and restoring focus to digital media consumption", which was explored at the last MEX, minor inconsistencies in UX language disturb the user from enjoying an immersive experience.

There's a term I learned from reading Daniel Kahneman's Thinking, Fast and Slow, a psychological principle known as "stimulus response compatibility". Essentially, it means that a cue suggests a certain behaviour. Like the green traffic light. Kahneman talks about the expectation that a door handle triggers the response "pull" but this is violated by architects time and again. How often do you find yourself pulling then pushing a door because there's a handle. I did it two days ago at a conference in the Shard. To confuse things further, one set of doors required a pull; the second, a push.

Whether opening a door or looking at pictures, we should not be required to switch to slow thinking. Maintaining consistency across stimuli should be a goal of the developer, so that the user can more fully engage with the content: the device and the app should become, to all intents and purposes, invisible.

So, thank you, Twitter, for making the change. I can no longer use your iPhone app as an example of stimulus response compatibility violation.