2.5.6: Concurrent Input Mechanisms

A Smart TV remote, which is an example of a device with concurrent input mechanisms. The TV accepts remote control and voice commands.

What are input mechanisms?

Input mechanisms are how we interact with technology. They include keyboards, mouses, styluses, and touchscreens. All devices come with a primary input device; for example, the keyboard and trackpad are a laptop’s primary inputs, while the touchscreen is a mobile phone’s.

However, there are times when the default input mechanism is not ideal. Imagine struggling with a clunky touchscreen keyboard and wishing for a more reliable physical keyboard, or a system accepting only typed inputs where a voice command would have been faster and more convenient. These are only two of the limitations of single input interfaces.

The Web Content Accessibility Guidelines (WCAG) outline the problems with single input interfaces in a level AAA success criterion, Concurrent Input Mechanisms. At the highest level of accessibility, websites and mobile applications should allow users to switch between different input mechanisms when they desire to. The idea of this success criterion is that technology adapts to the user, instead of the other way around.

Why are concurrent input mechanisms important?

Having concurrent input mechanisms means having the ability to use multiple input methods simultaneously or interchangeably. You can switch between touch, voice, keyboard, and even eye movements based on your own preferences. This empowers users to choose the most efficient and comfortable way to interact with technology.

In terms of digital accessibility, it is important to remember that no one uses websites or mobile apps in the same way. Some users with disabilities are unable to move a mouse around accurately, while others are not able to activate touch targets on a screen. Concurrent input mechanisms allow you to choose the input method that best suits your needs, therefore breaking down barriers to access.

It is also more efficient to have multiple accepted input mechanisms. Different tasks call for different tools and users will have certain preferences depending on the task. For example, searches are quicker with voice commands, while text editing is better with a keyboard.

Examples of concurrent inputs

  • Mobile devices: Many tablet devices and mobile phones now support keyboards as well as touchscreens. Users simply pair their keyboard with their phone and switch between touch and keyboard while interacting with websites and apps.
  • Smart TVs: Alongside traditional remotes, some smart TVs now allow voice commands and hand gestures as additional input mechanisms.
  • Augmented and virtual reality (AR and VR): Eye tracking technology and hand gestures can be combined to make immersive AR and VR experiences.

How do I implement concurrent input mechanisms?

Developers and designers should avoid the use of input-specific event listeners or hiding button and slider controls when a touchscreen device is detected. Don’t assume you know how your users will interact with your website or mobile app, and therefore block them from using more than one input mechanism. By ensuring all the functionality of your website can be done via both keyboard and touch, you will go a long way towards improving your digital accessibility.

How can IA Labs help?

As part of our consultations, accessibility audits, and training sessions, we can explain all of the contextual nuances that would apply to the WCAG 2.2 Success Criterion 2.5.6 Concurrent Input Mechanisms. If you have any questions or need help with any digital accessibility issue, please don’t hesitate to contact IA Labs.

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