If you're an iPhone savant who explores every last obscure feature of your iPhone, here's a headline: Most people aren't like you. Spend a little time with an everyday iPhone user (or for a real surprise, look over the shoulder of an iPhone newcomer) to see just how little they've explored the standard iPhone controls and especially touchscreen gestures—the taps, flicks, and swipes that make the iPhone do its thing.
This disinterest in learning gestures might seem odd since the iPhone's touchscreen is one of the things that was so revolutionary about the device—the innovation that makes the iPhone so effortless. And sure, even first-time users get the obvious physical metaphors immediately: swiping screens, tapping buttons, flicking number spinners, dragging maps. No problem there; you can count on those interactions because they work just like manipulating objects in the real world. Drag it to move it, tap it to push.
Figure 1-2. Familiar physical metaphors work well to suggest touchscreen gestures, even for iPhone newcomers. User tests show that first-timers instinctively get how to swipe a picker menu to spin its dials, as in Lose It! (left). In the Air Hockey app (right), newbies immediately understand that they can nudge the mallet with their finger to play.
It's when you get to mildly fancy dance steps beyond taps and swipes that you start to lose people. Even some standard gestures of the built-in apps go unknown and unused for a big swath of people. This is especially true for multitouch gestures, the ones that require more than one finger. In testing sessions, many iPhone users say multitouch feels awkward, including even the standard pinch gesture for zooming in and out. When possible, most fall back to a single-finger option—double-tapping a map, for example, to zoom in—a reminder that it's best to craft your app for one-handed maneuvers. (You'll learn more about optimizing for one-handed use in Rule of Thumb.)
Gestures, of course, are especially tricky to get across to users because they aren't a labeled part of the interface, and they're not easily discovered. In the built-in Maps app, for example, even self-described experts often aren't familiar with the two-finger single tap to zoom out. In other cases, custom landscape modes go unseen because users never think to tip the Stocks app on its side, for example, to work with charts. You can't assume that people will figure out your app's gestures no matter how simple, standard, or consistent. Treat gestures as shortcuts for actions that can be accomplished by another (though often slower) route, so that there's always a backup plan. You'll explore gestures more thoroughly in Chapter 8 and device rotation in Chapter 9.
We might forgive users for not instantly grokking gestures which are, after all, invisible, but even labeled icons and buttons go unrecognized, their meaning obscure to your app's newcomers. We're not just talking custom icons either. Even when icons are consistent across all the built-in apps, for example, uptake is slow on what individual icons represent.
Figure 1-3. Even some of the standard icons of the built-in apps cause confusion for newcomers. After several weeks of use, many users still don't realize the X icon in Safari's location bar can be used to clear the web address. Meanwhile, in user tests, first-timers often expect that the + icon, which is used to bookmark pages, will instead enlarge the page text.