Touch isn’t just inaccurate, but it’s inconsistently inaccurate. And what is most interesting is that the largest variable is not environmental conditions, familiarity with touchscreens or anything. It’s the position on the screen they are trying to tap.
We know that people are more accurate at the middle of the screen. And that’s pretty much any screen, any way they hold their phone or tablet. They also subconsciously know this — or it may be tied to their preference for reading in the middle — so are more confident at the center, but will slow down to tap corner or edge targets.
If we map the research to a screen the right way we can see how much more room is needed between items in various parts of the screen. The sides are a little worse than the center, but the top and bottom require much more room, and corners are the worst.
Figure 6—Touch accuracy varies by part of the screen, in such a consistent and predictable way you can use this to design your interface. Space items farther apart at edges, and especially along the top and bottom of the screen.
These neatly correspond to sort of structural zones that already exist in much of our design with content in the middle, and secondary labels and controls along the top and bottom edges of the screen.
Just space things out more along the top and bottom edges, and place unrecoverable or annoying-to-exit items far from others to avoid frustrating accidents.