1.6. Clumsy Fingers

Fingers are a dazzling engineering invention, capable of a whole slew of remarkable things: A finger can test the direction of the wind, plug a hole in a dike, test the temperature, and even direct an elevator to a specific floor. Fingers, however, are lousy at precision touchscreen interactions. A touchscreen stylus or a mouse pointer can easily hits its target within a pixel or two. In comparison, the finger is all thumbs. It's a blunt instrument that clubs whole swaths of pixels at a time and, to make things worse, obscures the screen so that when you're wielding this clumsy pointer you can't even see what you're pointing at.

Add a rushed and distracted user to the mix, and things get messy. People miss buttons, they tap the wrong target, they "overswipe" by tapping a bottom icon when they mean to scroll the screen. If you put more than a few tappable items on an iPhone screen, users will accidentally tap the wrong one sooner or later. Designing for touch takes careful effort and an attention to ergonomics that's new to many software designers. You'll explore these topics further in Chapter 3.