It is often assumed that touch-screens make handheld devices smaller, as these do away with the need for buttons. But paradoxically, they are often larger than the pushbutton gadgets they replace, according to Patrick Baudisch at the Hasso Plat¬tner Institute in Potsdam, Germany, and Microsoft Research in Redmond, Washington. It is hard to hit small touch targets on a screen because your finger hides what you are aiming for.
Baudisch and his student...
