How can the design of physical controls be standardized to ensure a consistent user experience across different devices?

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User interfaces are with us every day and help us to control complicated processes quickly and in a targeted manner. Digital input and output options are often linked to physical elements that give the user a more differentiated haptic experience. For example, rotary knobs and sliders can transmit the smallest changes to technical devices with great precision.

These physical elements in particular offer a high degree of safety and help users to learn complicated controls more quickly and avoid errors thanks to muscle memory. Although there are many advantages to physical user interfaces (PUIs for short), touchscreens are also being used more and more in the consumer sector. In the automotive sector in particular, it is becoming more and more prevalent, although drivers have expressed a desire to return to haptic buttons in surveys. There are many reasons for this, such as the fact that touchscreens are now cheaper to produce than physical controls. The visually modern and minimalist look is also still a selling point.

DIN EN ISO 9241-400, a part of the DIN standard for human-system interaction, deals with the rules for designing buttons,

knobs and other elements. But are the existing regulations still up to date in terms of inclusion and equality? And how can PUIs be standardized with these aspects in mind and from a design perspective to ensure a consistent user experience across different devices? In general, the question arises as to how physical user interfaces can regain relevance in the age of touch displays.

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