The question of “fat finger” mistakes on touch screens came up in conversation the other day, together with the idea of making targets large to avoid this. At first, it seems sensible to make hit areas for controls on mobile devices as large as possible. But it was pointed out that, counter-intuitively, smaller hit areas can decrease fat finger errors.
That is true to an extent, but as with all things HCI, it’s only a part of the picture. So I thought I’d try to summarise the issues, and to recap as a reminder to myself, if nothing else. What follows is the relevant parts of this excellent article by Steven Hoober, condensed for reference.