Bench Talk

(Source: New Africa/stock.adobe.com)

My electric kettle has capacitive touch buttons for power and temperature selection. It’s simple and gets the job done. But every time I’m in a home appliances store, I can’t keep my hands off the electric kettles that have a dial for temperature selection. It has just the right amount of resistance as it gently clicks around. The knob kettle costs several times more than my capacitive touch kettle and heats water exactly the same. Still, for many tea and coffee drinkers, the premium experience of having a knob is worth paying a premium. Our love of a great physical interface is the same reason why mechanical keyboards are so popular and why I get questioned by department store employees for touching every button on every coffee machine on display.

There’s no denying the utility of touch-based controls. But recent trends show that the sleek touch-based world we’ve found ourselves in is on the cusp of a button renaissance. What was a novelty not long ago, touch controls have become so ubiquitous that buttons are now a luxury, just like the kettle with a knob.^[1] In a race to optimize controls for cost and manufacturability, some designers have forgotten the “human” aspect of human-machine interfaces (HMIs). Now, manufacturers are answering consumers’ calls to reinstate the buttons.

Where Have All the Buttons Gone?

There’s no denying the benefits of touch-based user interfaces for small multifunction devices like mobile phones. As someone who was originally a physical button enthusiast and thought mobile phones with QWERTY keyboards were the pinnacle of phone design, even I learned to appreciate the extra screen space over a physical keyboard. Also, I didn’t have much of a choice. Aside from the now-discontinued Blackberry phones, most smartphone manufacturers chased sleek, keyboard-free styling.

Phones proved to be among the more exciting touch-based technologies, which seemingly led to buttons quietly disappearing on all kinds of appliances and devices. In lots of cases, it made sense. As devices took on more advanced functionality, nesting functions within touch menus made them easier to navigate. Office printers would have looked like airplane cockpits if they had dedicated buttons for every setting (Figure 1). White goods manufacturers also saw the benefits of swapping mechanical buttons for capacitive touch: lower cost, fewer points of ingress for dirt and moisture, and simpler manufacturing.

Figure 1: While touch screens may be easier to navigate, they’re much less satisfying than angrily jabbing a button with your finger. (Source: jummie/stock.adobe.com)

Touch Controls Push Consumers’ Buttons

Button erasure seemed unstoppable until consumers hit the brakes on touchscreens in cars. Intuitively, it makes sense that if phones are considered too distracting to use while driving, a dashboard-mounted tablet might also compete with the road for our attention. A growing body of research supports this intuition.

A paper from the Virginia Tech Transportation Institute found a striking difference in the number of times someone glanced at their center console for more than two seconds in a car with legacy physical controls and one with a full touchscreen.^[2] About 3 percent of the visual-manual interactions in the legacy car lasted over 2 seconds. In this context, a visual-manual interaction means looking at the center console and performing an input, like adjusting the air conditioning. In touchscreen-based consoles, the percentage of glances over two seconds for visual-manual interactions rises to 34 percent. This means that for a third of every instance in which a driver interacts with their console, they take their eyes off the road for at least two seconds. A car moving at 100km/h travels 55 meters in those two seconds. In American units, that’s the distance from the 50-yard line to the back of the end zone. Could you run that on a crowded field with your eyes closed?

Automakers around the world have re-examined their touchscreen-based interfaces in response to consumers not wanting to gamble with their safety to change their music or air conditioning while driving.^[3] Hyundai cites unfavorable focus group feedback with touch-based controls, while Volkswagen faces a class-action lawsuit against its steering wheel touch controls.^[4]

Beyond the automotive space, buttons have begun reappearing on consumer devices. Apple, an early trendsetter in button removal, replaced the mute switch with an Action Button on the iPhone 15, then introduced an additional Camera Control button with the iPhone 16. Household appliances are also switching back to buttons and dials, meaning you won’t have to worry about not being able to turn off your touch-based cooktop in the event of a boil-over.^[5]

Design That Pushes the Right Buttons

Buttons, knobs, and dials are more than just an engineering decision to optimize for price and performance. As the medium between the physical world and the digital world, buttons are the lingua franca between us and machines. A button with satisfying haptic feedback is like an active listener in a conversation. We feel reassured that our inputs are welcome and acknowledged. Anthropomorphizing a button may sound dramatic, but human-machine interfaces should feel inviting to a human touch. Users want devices that feel designed for human interaction.

[1] https://www.theatlantic.com/technology/archive/2023/02/buttons-on-gadgets-resurgence-nostalgia/673102/
[2] https://vtechworks.lib.vt.edu/items/d82eb376-1256-41f3-98c5-11ea9c19ef0e
[3] https://www.jalopnik.com/1995818/car-brands-bringing-back-physical-buttons/
[4] https://www.jalopnik.com/1944408/vw-owners-suing-capacitive-touch-buttons/
[5] https://www.wired.com/story/touch-controls-on-stoves-suck-knobs-are-way-better/