An OLED display can present selected numbers to provide more concrete data about the user’s activity, such as calories burned, number of steps taken, distance walked, and so on. The activity trackers LG Lifeband and Withings Pulse are two products that use this display (see Figure 4-20). To keep the display as small as possible, the metrics are rotating on the same display area, either automatically every few seconds or by using a gesture or clicking an on-device button to switch between the numbers displayed.
Figure 4-20. The Withings Pulse (top) and LG Lifeband activity trackers
Minimal-display wearables are not limited to activity and health trackers alone. For example, the Razer Nabu shown in Figure 4-21 uses an OLED display to present a variety of notifications (which the user can customize), including call, email, text messages, and social network notifications, calendar alerts, and more.
Figure 4-21. The Razer Nabu shows selected notifications by using an OLED display
The Razer Nabu is similar to the Pebble watch in terms of its value proposition. The main differentiator is its focus on privacy and discreteness, which is also manifested in its unique UI design. The Razer Nabu is built with a dual screen, as shown in Figure 4-22 — the one on the top is visible to the surroundings (“Public icon screen”), and the second display on the bottom is visible only to the wearer (“Private message screen”).
Figure 4-22. The Razer Nabu’s dual-screen operation
When a call, message, or notification arrives, the public part of the wristband shows only the event category (for example, a call or message icon). To view the actual content — which could be private — the wearer rotates his arm to reveal the details of the event (for example, the caller ID or message text).
Even though this design cleverly addresses privacy concerns, I can’t help but wonder if this use pattern, which requires the user to repeatedly rotate his arm back and forth, will quickly lead to ergonomic issues, especially given the variety of notifications Razer Nabu integrates, and the increasing frequency with which people receive (and check) these notifications.
Minimal display wearables can also combine both types of visual feedback, lights and numbers, as in the case of the Nike+ FuelBand, which is depicted in Figure 4-23.
Figure 4-23. The Nike+ FuelBand provides both exact numbers (such as numbers of steps) along with a visual
indication about the progress in relation to the daily goal
With this combined approach, the user gets more comprehensive data about her status, accomplishments, and goal completion, which could contribute to her ongoing engagement with the device. However, it comes with a visual cost: the display becomes busier and less slick. Some of it has to do with the specific visual design applied (font size, colors, and so on). However, it is mainly tied to the amount of information that is displayed on the device.
This aesthetics-functionality trade-off emphasizes a fundamental question that wearables raise: how much information do people need to see on a wearable device versus viewing it on other ecosystem devices (a smartphone, for instance) to stay engaged with the experience ?
This question doesn’t have a simple answer — especially given the novelty of this industry and that it hasn’t penetrated the mass market just yet. Also, as with most UX issues, the behavior depends on multiple factors, such as the type of wearable, the use case, the specific user group, the context, use patterns, and more. We still need a lot more user data and research to understand this aspect.
With that having been said, when I look at the case of the combined displays shown previously, I lean towards a single indicator (preferably a simple visual cue) for overall progress. It not only establishes a cleaner interface, but also offers a much simpler flow for users to grasp, follow, and act upon. The famous premise “less is more” is becoming practically sacred when it comes to wearables. Given their small size, interaction limitations, and interruption-based use pattern (more on this in a moment), keeping the UI clean, clear, and glanceable is key to their usability.
Looking ahead, I think a projected display can help minimal-display wearables in addressing the fashion-function trade-off. Instead of the device itself having a physical screen component, it could project the info using some gesture/button click on an adjacent surface, whether it’s some body part (like the dorsal of the hand), a physical object, or even thin air. This way, rough progression indication (using lights, for example) can be immediately accessible on-device, but concrete numbers will be projected on an external surface. This will still permit quick
access to this data directly from the wearable while keeping the device design more aesthetic, clean, and elegant.