UIScape

More and more computing power is being put into handheld devices like mobile phones. A wealth of applications that were previously only available on desktop computers are now available in the palm of your hand. Taking these applications with you on the move is often as useful as the designers hope, but once as I tried to complete a game of Monopoly in London’s Victoria Station at rush hour, I knew that I was doing two things that were fundamentally incompatible with each other. 

A group of Finnish researchers have asked the question: just how much does a busy, demanding real-world context affect the user’s interaction with mobile devices? The answer, in case you’re walking across Victoria Station too, is a lot.

In fact, this study clearly demonstrates that mobility itself - the very thing we value mobile phones for - directly limits our ability to use mobile applications.

The researchers argue that we can‘t be mobile without dedicating some of our precious cognitive resources to maintain our position in the world. We have to commit social tasks like maintaining a sense of privacy on a crowded train, by monitoring the position of others and then shifting position appropriately. We also have to commit navigational tasks when mobile, like finding our current location, planning a route, walking purposely to avoid oncomers, buses, and so forth. Simply put, the time we spend thinking about these things means we can’t think about the device we’re trying to use at the same time.

                                                   ^{Image courtesy of evanrude}

This paper gives an idea of just how much our attention falls away in demanding mobile settings. In the lab, the participants looked at the mobile screen for an average of about 14s before looking away. When the participants were on a busy street, it was only 4s - less than a third of the time. This pattern continued throughout many measures: the strongest in my opinion is that in the lab, participants looked at their external environment for only 5% of the time they were using the device, while in the busy street participants were distracted enough that they looked away from the screen 51% of the time.

Two small quibbles with these figures is that they only measured visual attention, and only while a new internet page was loading. We can attend to our external environment in ways other than looking at it, and we’re more likely to look away from the screen while it’s loading than at other times. So I’d say keep in mind the ratios between the figures, rather than the absolute values.

And clearly, the users were in a difficult position: trying to use this new device while not walking into anyone or anything. How did they cope with these conflicting demands? The researchers reported that users seemed to pay lots of attention to a setting just after they entered it, then settled into long periods of using the device, punctuated by brief periods of attending to the environment. Perhaps most interesting, the researchers noted that when the environment demanded social interaction, users almost always stopped using the mobile device until the social demand was fulfilled. This hints that users give social demands a much higher priority than using their device.

For those of us looking to design, this paper is worth knowing about because it provides some hard guidelines to a previously intuitive idea of mobile contexts. For instance, don’t dream that your users spend as long as you do looking at the screen: count on 4s of your user’s time before they have to look away. You might get half your users time if they’re busy, so respect what time you get. Provide a simple, fast, easy-to-scan interface. Let them finish quickly, so they can get on with the more pressing task of making their way across Victoria station.