On my way through the San Francisco International Airport last month, I stopped at one of the new automatic water dispensers to fill my water bottle. I set my bottle down below the spigot and waited for the water to come out, as is common with most of the automatic dispensers currently on the market. However, when nothing happened, I began waving my hand around the machine in an attempt to find the sensor, while simultaneously looking around to see if anyone noticed how silly I looked. 

It turned out that the sensor was on the right-hand side of the machine, and it only dispensed water when my hand was actively held in front of it. This meant that for the duration of the 40-second fill, I had to stand with my arm extended in front of me. I felt a bit like a weak Jedi vainly attempting to use the force to very slowly fill my bottle. I found myself laughing and taking a video to show my friends.

This experience left me questioning the benefits of not only this water dispenser, but many of the touchless technologies that are being developed. In this post, I want to introduce the benefits and challenges of touchless UI and discuss whether these new technologies are helping or hindering our daily lives. 

What is an Affordance?

An affordance is a characteristic of an object that signals how to use that object and what actions can be taken. For example, a doorknob affords turning, a chair affords sitting, or a button affords pushing. They’re the cues that tell you how to use something. 

What is Touchless UI?

Touchless UI, or “natural UI,” is a way of interacting without having to physically touch an interface. With touchless UI, we rely on our other senses, such as voice or gestures, to interact. 

Touchless UI has been implemented in a number of markets, such as the creation of hands-free driving, to make our lives both safer and more efficient. And now with covid precautions, we’re seeing more touchless interactions than ever before. However, there are just as many touchless UI developments that raise the question of whether they are solving a problem or searching for one. 

Benefits of Touchless UI

Both voice and gesture recognition UI are developing technologies and provide incredible opportunities to change the way we interact with devices. The benefits of touchless UI can be innumerable, and include things like: 

• Increased efficiency, speed, and simplicity
• Reduction in visual clutter
• Reduction in the number of surfaces touched and germs spread

Challenges of Touchless UI

Touchless UI has the potential to be a great asset to users if it can surpass the challenges it currently faces, including: 

• People don’t read. Therefore, interactivity must be communicated in other ways. This can be challenging when there are no buttons, instructions, or other characteristics that signify how to interact with the interface. 
• Accessibility. Gestures cannot require fine motor skills or complex interactions that aren’t easily performed by everyone. 
• Gestures are not intuitive. Touchless UI is only beneficial if users can immediately understand how to use the technology. If it is not easily understood, it is creating problems rather than solving them.  
• Gestures require too much effort. Research on touchless UI shows that users are unwilling to perform large, prolonged or laborious gestures. 
• Gestures are awkward. Especially when using touchless technology in public settings, users do not want to complete gestures that are unnatural or away from their bodies, as these can draw unnecessary attention or create awkward interactions with others. 
• Expensive to design, test, and implement. When compared to their basic counterparts, touchless UIs take much more time and money to create.
• Usually a solution in search of a problem. When touchless UI is implemented simply for the sake of updates, rather than to solve a problem, it can cause dissonance between our senses and make the experience feel disjointed. This can be jarring or off-putting to users. 

Best Practices for Touchless UI

In my opinion, there are currently more challenges associated with touchless UI than benefits. Touchless UI can only be beneficial if it follows some general best practices. 

• To be effective, make it natural. For example, having users put their hand under the paper towel dispenser to dispense a paper towel makes sense because your hands would naturally go there to perform that action if the machine was not touchless. Asking users to gesture above the paper towel dispenser would be unnatural and unintuitive. 
• No fine motor interactions. Ultimately, it’s important to ensure that the s UI is accessible to everyone. 
• Stick to conventional gestures and movements. Any gestures that the technology requires should be commonly used, simple, intuitive, and easy to repeat. For example, it is best to stay away from gestures that may have another context such as waving or raising certain fingers. 
• Keep gestures small, close to the body, and short. Gestures shouldn’t require full extension. Touchless UI isn’t perfect, and a second or third attempt at a gesture is sometimes required. Small, short gestures ensure that repeating the movement is easy, doesn’t take too much time, and doesn’t make the user feel self-conscious. 
• One hand is best. One-handed gestures are not only more accessible; they are also more convenient, as people are frequently unable to free up both hands. 
• Leverage as many other senses as possible. Leveraging multiple senses, such as audio cues, pictures and icons, or lights, helps to make touchless UI more intuitive and efficient. For example, when you wave your hand under an empty automatic soap dispenser, it could make a noise or light up, indicating that your gesture was successful even if soap wasn’t dispensed. Simple additions like these can drastically improve user interactions.  
• Be reliable with a fast response time. If a user puts their hand beneath a soap dispenser and it takes 5-10 seconds to activate, they will have moved on well before the soap is dispensed. It is therefore important to not only be reliable, but to work in a timeframe that makes sense to users. 

Takeaways

The COVID-19 pandemic has already sparked a large increase in the number of voice and gesture designs on the market. As technological advancements continue, I think we’ll continue to see a much larger adoption of touchless UI. However, as we continue to implement these technologies, it is my hope that we will continue to leverage as many senses as possible while making gestures affordant and natural. After all, we ultimately want to feel cool like Tony Stark, not like a second-rate wizard unsuccessfully waving our wand at a water dispenser that refuses to work.