Balancing usability and delight in mobile user interfaces

Recently, while stumbling through the bowels of the internet, I unearthed a mildly-scathing 2010 usability report on the iPad written by Jakob Nielson. If you don’t know, he's something of a usability guru—often, critics say, at the expense of even vaguely attractive design. Regardless, the guy makes good points and and has outlined some pretty helpful and timeless web heuristics that definitely earn him some serious street cred. I don't have an iPad, so I'll discuss his findings only insofar as they apply to the iPhone as well.

Now this study is a little dated, but I have a hunch that Nielson’s impressions on iOS usability have probably not improved with the advent of iOS 7. And even as an Apple lover, I can’t deny that he makes good points, many of which still hold true. For example, a few of the key usability shortcomings he describes from his iPad study, which can apply to all iOS devices, are:

  • Low discoverability (meaning controls are hidden from plain sight, perhaps requiring a gesture that isn’t immediately obvious),
  • Low memorability (because navigation and conventions aren’t consistent between apps), and
  • High risk of inadvertent actuation (because swipes, pinches, taps, and holds can occur by accident without the user registering what has happened).

Through an empathetic and objective lens, it's easy to see what he’s getting at. Imagine deleting a text or email conversation in iOS: you have to swipe left over the conversation to reveal the “delete” button.

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No clear affordances inform users of this function (low discoverability) and for the same reason, users might not remember the function the next time (low memorability). Likewise, users who have not yet discovered this function might inadvertently swipe left on a message, thereby revealing the delete key without knowing how they did it (inadvertent actuation), although iOS 7 manages this confusion better than did its predecessors.

Certainly, Neilson uncovers some poignant findings, but my question is this: where do we draw the line? Should we sacrifice fun, enthralling design for maximum usability? Here’s the thing: usability is undoubtedly important, but it’s not the only component of the user experience. Our relationships with our devices are as much emotional as they are rational. Our tasks are not purely utilitarian; users also benefit from beauty, elegance, and delight. To sacrifice those emotional experiences in the name of 100% usability, I think, would be a travesty. Balance is key. Beauty should not be a martyr to usability, nor should the reverse be true. When attempting to balance usability and a delightful experience, I propose considering the following three heuristics:

  1. First and foremost: always consider the use scenario
  2. Infuse delight and whimsy in secondary and tertiary functions. Prioritize usability and discoverability in primary functions 
  3. Be redundant wherever reasonably possible, particularly with unconventional controls

Consider the use scenario.

Is the user trying to pay a bill? Check the weather? Buy something? These are arguably utilitarian, goal-oriented tasks. Users want to accomplish the task and move on. To the surprise of absolutely no one, the Amazon shopping app is an outstanding example of straight forward, goal-oriented design. Functions aren’t hidden behind potentially ambiguous swipe gestures. Calls to action are large and clear. You probably won’t feel an enormous amount of “delight” when using this app—its features are unlikely to make you “ooh” or “ahh”—but when you can place an order in record time, your overall experience is overwhelmingly positive. 

Contrast that experience to something significantly more trivial: the popular dating app, Tinder. Tinder users might have… umm… “goals"… but the experience of interacting with Tinder is more exploratory in nature compared to shopping on Amazon. Accordingly, there is more room for “delightful” interactions, like using swipe gestures to navigate between navigation elements as depicted below (starring Matt… hi Matt!)

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While this navigation lacks obvious affordances, I argue that the delight associated with the movements on screen enhances the experience—particularly for the young, technically savvy users that define the service. Everything about the use scenario—user demographics, time constraints, time of day, expected user state of mind—determines whether the design should be straightforward and utilitarian, delightful and exploratory, or something in between.

Implement redundant functions where possible.

While we’re on the topic of Tinder, I’ll point out that the popular dating application also uses redundancy exceptionally well. Consider the swipe navigation outlined above. Some users, understandably, might not intuit the ability to swipe between those different navigation elements. These users need not fear; tapping the icons on the upper right and left sides accomplishes the same task. Furthermore, the animations associated with those actuations lead the user to possibly intuit the existence of the swipe functionality for the next time. Plus, as an added bonus, the app has helpful, non-intrusive on-boarding to guide users through the UI during their first use. In essence, Tinder's redundancy provides guidance for new users—who might not realize the swipe functions initially—while also providing a faster, more elegant way of accomplishing the same goal for experienced users.

Infuse delight at the *slight* expense of usability only in secondary and tertiary functions.

One of my favorite delightful features on the iPhone is the ability to “pull” the text messages to the left to reveal the precise send and receive times. At first I didn’t know how to find this information, but discovered it by playing around, and literally felt giddy when I found this fun and clever UI element. 

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Yes, this feature compromises discoverability. But precise text-sending time is far from an interface priority for the majority of users, especially because the iPhone provides an always-visible timestamp every so often. Accordingly, the team at Apple opted for simplicity and delight over 100%, in-your-face usability. And for this particular function, I think they made an appropriate call.

Certainly, though, this requisite “exploration" can be exceedingly frustrating when applied to primary functions. I love Spotify, but the function for skipping a song from the main screen—a primary action used when listening to music—is too difficult to discover. When a song is playing, it appears in a bar at the bottom of the screen, and can easily be accessed by the user’s thumbs. The pause button is clear, but in order to skip a song, the user is expected to swipe left over the duration of the bar. Even as a savvy tech-lover, it took me several frustrated seconds to figure this out. My mother would have thrown her phone out the window before discovering this hidden function.

Conclusion

I would never dream of denying that usability is important, and in the design of home hemodialysis machines, air traffic control towers, and nuclear reactor control panels, it is indisputably paramount above all aesthetic considerations. In consumer tech, however, usability is only one component—albeit, an important one—of the user experience. By keeping users’ specific use scenarios in mind, making controls redundant, and only using experimental or unconventional controls for secondary and tertiary functions, we can effectively manage usability and delight without sacrificing either. While Nielson's findings undeniably hold water, he and I seem to disagree on one thing: to me, "discovery" is not necessarily an onus—sometimes it's part of the fun.