Designing for Wearables

Wearable technology encompasses a diverse range of devices that can be worn on different parts of the body, each serving distinct purposes and presenting unique design challenges.

Let's look at the most popular types of wearables available today:

• Sports and fitness trackers: People usually wear them on their wrists or clip trackers on their clothes to count the steps taken, calories burned, distance traveled, or hours slept.
• Health and medical sensors: These devices help monitor physiological parameters such as heart rate, respiration rate, ECG (electrocardiograph), temperature, emotional stress, dehydration, glucose level, and even posture.
• Smartwatches: Smartwatches are best fit for receiving notifications, calls, and messages, making payments, tracking activities, setting an alarm, GPS navigation, and remotely controlling music.
• Smartglasses: Smartglasses project a computer screen onto the lens and allow people to complete hands-free tasks like checking notifications, taking photos, and searching.
• Ear-worn wearables: The ear-worn wearables or hearables present the largest product category in the wearable device market. They're connected to Bluetooth devices (a smartphone or laptop) and deliver audio content through them.

Smart rings, smart clothing, smart shoes, sleep trackers, and smart tattoos are also gaining popularity in the wearable device market.

The term "glanceability" refers to the most important principle in designing wearables with displays. It means that wearable devices should be designed in a way that users can understand what's going on with just one glance or interaction with them. Glanceability is less about reducing the amount of content to its basics on a screen and more about researching user needs and finding out what information they would like to see at specific moments.^[1]

Unlike smartphone or tablet interfaces, wearables are not meant to hold a user's attention for long. Users want to spend as little time as possible interacting with them and prefer not to scroll through content. Additionally, people often use wearables on the go — while jogging, exercising, commuting, walking a dog, or shopping. The goal is to help them instantly access the information they need and continue with their activities.

Information that is delivered on time is what makes wearable devices valuable. Applications may use device sensors to get context clues about what users are doing and provide helpful and relevant insights. For example, smart posture belts worn around a person's waist can register body movement and send users notifications to the respective app if they slouch.

Collaborating with built-in device sensors will help designers prevent being intrusive and help send only relevant alerts that provide information that matters. Additionally, your app can cooperate with device services like geolocation and use it to improve usability. For example, a smartwatch can use GPS to provide real-time navigation updates for runners, suggesting optimized routes based on their location and pace.

While most other mobile device interactions may take users a few minutes, wearable interactions should be kept to a few seconds. How can you accomplish this?

• Minimize input. Typing on a smartphone can be tiresome, but typing on even smaller screens can become a nightmare. Provide predefined answers or allow voice input to avoid frustration.
• Keep it to one action per screen. Don't distract users by offering them too many options on a tiny screen. One action is enough. And don't forget to make the primary button easy to spot.
• Don't force users to scroll. Whenever possible, keep the information short and avoid making users scroll. Alternatively, you can break content into several screens.
• Provide accessible touch target zones. Unlike smartphones, which users usually navigate using a thumb, smartwatches or fitness bracelets are mostly accessed with an index finger. Keeping this in mind, interactive elements should have the appropriate size and spacing between them on the screen.
• Use concise language. Stick to short and common words to deliver information and accompany text with relevant graphics (icons or graphs) if necessary. Users should need only one glance to grasp the content.

The KISS principle (keep it simple, stupid) is vital when it comes to design for wearable devices like smartwatches, fitness bracelets, or medical sensors. Their screens are tiny and can only contain as much information as users can consume in under 10 seconds.

What can you do to simplify UI on wearables?

• Focus on user needs. You can't decide what information is essential and what can be removed if you don't know what your users need. Conduct user interviews and user testing to find out if the app meets user expectations.
• Choose colors wisely. Most wearable screens use black backgrounds, so designers should follow dark mode principles and minimize visual clutter. Careful color choices ensure readability and contrast.
• Choose legible typefaces. Sans serif typefaces are considered more legible, help scan information more efficiently, and don't distract users from reaching their goals.
• Use simple UI elements. Avoid menus, lists, accordions, breadcrumbs, or other UI elements that ask for too many interactions to reveal information. Keep relevant data visible or break it into several screens with simple swipe navigation.
• Provide enough space. If users can't scan and read information, your app will fail to serve its purpose, so make sure elements are adequately spaced and don't overlap.

A constantly buzzing phone is annoying enough, but a constantly pulsing device against the skin goes way beyond annoying. If they get too many notifications, users will switch them off or start removing apps.

You can prevent this by minimizing interruptions in the following ways:

• Minimize the number of notifications. Wearable devices are generally tailored to serve specific needs. So, the amount of information your app provides your users should be limited too. Avoid sending repetitive notifications frequently and show respect for your users' time.
• Keep notifications relevant. It requires research to understand what notifications users find helpful but it's key to your app's success.
• Allow customizing notifications. Sometimes, even valuable notifications may seem distracting. Allow users to control notifications and configure their timing, frequency, and type.

In contrast to smartphones, wearable devices are in plain sight all the time and can reveal confidential information like conversations, health, or banking data.

To protect user privacy:

• Consider showing previews of notifications on default, and display more personal content only when users interact with the device.
• When the device's screen faces outward, show a blank screen only.
• For enhanced security, consider offering users the option to switch on password or fingertip protection.

Most wearable device apps partner with companion apps running on a desktop or other mobile devices. It's crucial they look consistent and provide similar functionality and user experience. Consistency in terms of colors, typography, navigation, and vocabulary inspires trust, minimizes the efforts users need to get familiar with an app, and makes products look professional. A wearable app might provide limited content or functionality but users should still get the impression that they are using the same product.