Design Principles for Mobile Search

Apple’s iOS Human Interface Guidelines and Google’s Android Design Guidelines both provide valuable guidance for designing general mobile applications. But there are a number of design principles that can help us achieve effective mobile search experiences in particular. Namely, most mobile search applications should prioritize content over controls, provide answers over results, and ensure cross-channel continuity.

Content Trumps Controls

Search, as the last few chapters have shown, is usually accompanied by a number of knobs and dials: filters, breadcrumbs, sort controls, pagination; the list goes on. When moving from the design of desktop to mobile search interfaces, the temptation is to replicate all of these controls on the main search results screen. Yielding to this temptation, however, leads to cluttered, frustrating interfaces that add stumbling blocks to the user’s path.

The primary search screen of a mobile application should be focused on the clarity of search results; bells and whistles must take a back seat. Mobile users, after all, often use their devices for short bursts of time, enter fewer queries per search session than do desktop users, and often seek answers to simple, lookup-based information needs. These realities suggest that navigation bars should be kept to a minimum, filtering and sorting displaced off-screen, and pagination controls omitted so that the search results receive as much screen space as possible.

Kayak.com’s mobile website—with four rows of controls and a large advertisement—clearly fails to adequately prioritize its search results.

Answers over Results

In addition to minimizing search controls and emphasizing content, focusing on precision over recall can make search more efficient for mobile users with lookup information needs. Precision, you’ll remember, describes the accuracy of the top results. Because mobile users reformulate their queries less often than desktop users—and are more likely to use their devices for short bursts of time—prioritizing the relevance of the top few results is generally more useful than delivering high recall.

Providing direct answers to users’ lookup queries can make the mobile search experience more efficient still. Rather than force users to click on a search result to discover straightforward facts, such as “director of third man movie”, a more desirable approach is to provide a computed answer directly on the search page, eliminating the need for further action.

However, both of these approaches—emphasizing precision over recall and answers over results—are optimized for short-term, lookup-based information needs, and will have diminishing returns for learning and investigative motives where users are willing to invest greater amounts of attention. In other words: it depends on the user’s context.

Google sometimes provides direct answers to the user’s query.

Cross-Channel Continuity

Every business recognizes the value of consistency across channels: customers benefit from a coherent, holistic experience where the learning from one channel can be applied to all the rest. A user familiar with Amazon on the desktop will instantly recognize the similarity of Amazon’s mobile application, for instance. But while consistency ensures the learnability of each channel, continuity makes it personal. Continuity is adding an item to the shopping cart via a desktop computer, and having it appear in the shopping cart on your phone; it’s saving a search on your phone and returning to it later on your tablet. In other words, continuity ensures that your actions aren’t performed in isolation, but propagate from the source channel to each of the others.

Mobile users only satisfy 45% of their information needs at the time they arise, with 25% being completed later and 30% not at all. Continuity between channels can enhance the figure-it-out-later approach often taken by users, as well as reduce the number of information needs that fall through the cracks. For starters, search history should be synchronized across devices so that inconclusive information seeking can be easily followed up later. What’s more, facilitating saved searches that can be accessed from every channel enables users to organize and return to important, ongoing information needs.

Zillow allows users to save searches, but fails to synchronize them across devices.

About Tyler Tate
Tyler Tate

Tyler Tate is the cofounder of Twigkit—a Cambridge-based software company that provides tools for rapidly building search-based applications. He is also coauthor of Designing the Search Experience, and has written articles for the likes of A List Apart, Boxes & Arrows, UX Matters, and UX Magazine. In the past Tyler led design at Nutshell CRM, designed an enterprise content management system, ran a small design studio, and taught a university course on web design. He blogs at tylertate.com, and tweets as @tylertate.