Designing UX for Natural User Interfaces

Before smartphones, tablets, and trackpads we had keyboards and mice. Our devices were connected to us through peripherals that interpreted our input graphically. Scrolling and selecting was done with the click of your mouse or a keystroke. And now we've evolved to swiping and tapping to interact with devices.  That got me thinking about how we use gestures in the digital world. And how the user experience with these gestures helps make them intuitive and fun to use. That’s where natural user interface, or NUI, connects with UX. In this article I’ll cover a few basic principles of NUI, and how you can use them to design great UX.

What is NUI?

First let’s start off with a bit more on what NUI is. There are a lot of different definitions out there, but I really like how Ron George, NUI/UX designer for Microsoft puts it:

Natural User Interfaces are just a way of explaining the method you interact with machines. Some machines require tools, like a remote control, keyboard, or a mouse. People who specialize in designing natural user interfaces challenge themselves with designing methods of interacting with machines that require no tools other than the ones you were born with. - Ron George

Make it comfortable

Even though most of us would love to have a Minority Report-like office, the reality is that after a few minutes of holding your arms up (like Tom Cruise’s character does all day) you’d have to take a rest. Your users should be able to naturally and comfortably interact with your device. If a gesture is uncomfortable or too repetitive, the experience won’t be great for users. And don’t forget about accessibility, either. Some gestures might not be possible for users with disabilities, so make sure you’re factoring in the use of assistive technology devices like joysticks or electronic pointing devices.

Design for fingers

Touch screen interfaces are one of the most common examples of NUI in action. Your fingers and thumbs are your direct link to your device, and the interfaces should be designed with them in mind. Touch targets should be large enough to respond to your finger with enough space to avoid accidentally selecting nearby links. Also make sure everything the user wants to access is placed in a useable range. For example, mobile users may depend on using just one hand while browsing a site, so avoid using complicated, two-handed gestures or placing information at the bottom of the screen, where their hands could obstruct the information.

Use easy gestures

Working with a NUI shouldn’t require a complicated, secret handshake. If a gesture is too difficult to perform (or remember) some users  may not be able to perform it, and others just won’t if it’s too much work.

Avoid everyday gestures

There are some gestures we use every day without thinking, like waving to someone or shaking hands. Steer clear of incorporating gestures like these as they could lead to a lot of unintentional interactions with a device when users are just going about their day.

Start simple

User adoption is important, especially when introducing a new way to interact with a device. Use simple, intuitive gestures (like tapping or swiping) to help users feel comfortable with the interaction. Great UX evolves with users. As gestural interactions and the interfaces that use them become more popular, UX professionals need to factor in a new level of interaction when designing great experiences.   If you’d like to learn more about NUI, check out Daniel Wigdor’s book, Brave NUI World, or check out this video about Google’s Project Soli—a gesture recognition sensor that uses radar signals.