There’s a “best way” to press a button, apparently – and we could use it to make buttons great again
The Sugababes made it sound so easy. “If you’re ready for me boy, you’d better push the button and let me know,” they sang. The act of pushing the button was seemingly so simple that the authors (Buchanan, Buena, Range et al., 2005) expended no more of the song’s other 450 words on how a button should be pushed for optimal performance. No more clues can be found in Buttons by the Pussycat Dolls, The Hardest Button to Button by The White Stripes or 1947 classic Buttons and Bows, so now what?
Help is at hand, from Aalto University in Finland and KAIST in South Korea, which have created detailed simulations of button-pressing to study how we press them. The way one squeezes a remote control, for example, is very different to the manner in which a skilled pianist tickles the ivories.
“The press of a skilled user is surprisingly elegant when looked at terms of timing, reliability, and energy use,” said Professor Antti Oulasvirta from Aalto University. “We successfully press buttons without ever knowing the inner workings of a button. It is essentially a black box to our motor system. On the other hand, we also fail to activate buttons, and some buttons are known to be worse than others.”
The researchers revealed that physical buttons with actual travel were more usable than touchscreen buttons, but that the very best buttons were those that reacted in time with the maximum impact. With this in mind, the researchers designed what they consider to be the ultimate button using “impact activation” – meaning that the buttons only function when fully pressed. The researchers found it to be 94% more precise in rapid tapping than regular push buttons, and 37% more accurate than a regular capacitive touchscreen virtual button.
This might all sound a bit over the top for something as simple as a button press, but it’s actually not as trivial as it might first appear. Muscles in the finger are imperfect and don’t behave in exactly the same manner every time, for one thing. For another, a button press takes around 100 milliseconds, which is way too fast to finetune movement. With this in mind, the researchers were more interested in how the brain learns from this experience to perfect future button pushes.
Their conclusion? The brain uses a probabilistic model, where is has inbuilt expectations about how a given button should be pressed, be it a space bar or a quiz show buzzer, and predicts a motor command for the circumstances. If that fails, it has a backup press it can fall back on, and so on. “Without this ability, we would have to learn to use every button like it was new,” says Professor Byungjoo Lee from KAIST.” Once a button is successfully pushed, the brain finetunes the motor command for more precision, less energy and to avoid pain in future. “These factors together, with practice, produce the fast, minimum-effort, elegant touch people are able to perform,” argues Lee.
Although the researcher’s button design can be easily added to touchscreens, it’s still not the ideal format, as anybody who has every tried to type out a long email on their smartphone will already know. This, the researchers believe, is in part down to the tactile feedback, which is more pronounced and longer with physical buttons.
“Where the two button types also differ is the starting height of the finger, and this makes a difference,” explains Lee. “When we pull up the finger from the touchscreen, it will end up at different height every time. Its down-press cannot be as accurately controlled in time as with a push-button where the finger can rest on top of the key cap.”
Perhaps more importantly, button pressing is an acquired skill, rather than something we just do instinctively. “We believe that the brain picks up these skills over repeated button pressings that start already as a child,” explains Lee. “What appears easy for us now has been acquired over years.”
In other words, make sure your children don’t just use tablets and phones, otherwise, the Sugababes’ best song will be completely lost on them. And, y’know, typing will probably be harder going too.