The common view before this work was that the lack of physical buttons is critical, but you also have tactile feedback from the surface of a touchscreen. Another false belief was that touchscreens are slower, but that is not the case anymore, Dr. Byungjoo Lee explains.
The group conducted experiments where participants were asked to tap a display when a target would appear. The data showed large differences between physical keys and touchscreens in how reliably users could time their presses.
– We found a systematic pattern in timing performance that we could capture mathematically, Dr. Lee tells.
“We can finally explain why games that require accurate timing are annoyingly hard on touchscreens,” said co-author Antti Oulasvirta in an accompanying news release.
First: Users can’t know how high to hold their finger from the screen, which is not an issue with a physical button. In a physical button, you have to maintain physical contact,This introduces variability in timing.
Second: A player can’t reliably tell when the touchscreen will actually register a touch. Is it when the finger makes the slightest contact? Is it when it passes some threshold? The timing of the sensor is very uncertain.
Third: depending on a number of factors, a registered touch will take effect quickly, sometimes not. Latency is unpredictable within games and apps. This is entirely out the hands of the players.
Adding to the problem there are some solutions: As for finger height — unfortunately, there doesn’t appear to be a solution, but for minimizing and regularizing latency, for one thing, is always a good practice. And by making touch events only take place at a certain “touch-maximum” threshold, reliability and accuracy were increased and error rates dropped by 9 percent.