March 2, 2011

Seven Rules for Designing Mobile UX

Licensed under Creative Commons. Photo by Ed Yourdon -

Focus on narrow, specific tasks. It doesn’t take a survey to tell you that users are less focused when they are using browsers and apps on a smartphone. This means that you should focus your design on a small set of well-defined tasks. Don’t try to squeeze everything under the sun into a single app.

As an example, look at how the Harvard Business Review has broken out small domains of content into separate iPhone apps rather than squeezing their large archive into a single feature-rich app.

You have to rely on the user’s memory. Because of small screen size and awkward input modes deep, hierarchical navigation schemes are almost impossible in mobile apps. Instead you have to rely on the user’s short-term memory to build a mental model of your information space. This means preserving state for the user, presenting fewer options and making extensive use of a back button.

Think hard about mobile input modes.
Users can’t spend precious seconds typing long text strings or URLs into your app. Find ways to take advantage of the new input modes that are provided by phones. Accelerometers, cameras and touch screens all give unique options that go beyond the mouse. A great example: accelerometer scrolling in Marco Arment’s iPhone app Instapaper eliminates the swiping usually need to read a long article on the smartphone’s screen.

Focus more on clickstreams than on wireframes.
With a typical Web site project we will spend about 25% of our information architecture effort creating a site map and clickstreams. About 75% of our time is spent creating page wireframes. When designing a UX for mobile devices this proportion is reversed. Individual screens are simplified, meaning less wireframing, but we have to spend additional time to ensure that paths through the UX are simplified and don’t tax the user’s memory.

Consider the relationship of the mobile experience to the Web experience. Users switch between a mobile and a Web context constantly. Many tasks are begun on one platform and finished on the other. In switching, users expect to be able to pick up their tasks easily and quickly between platforms. Intuit’s online personal finance software, Mint, is exemplary in supporting detailed tasks like budgeting on its Web platform while giving quick transaction access on it’s smartphone platform. The complementary nature of the two views into the same application provides a quick way to switch depending on the user’s context.

Make login and onboarding as painless as possible. Only the simplest of applications do not require users to register or go through a setup process. This step can be one of the most important for users and can also be one of the biggest hurdles. Input modes for text like usernames and passwords can be awkward and tiring on a mobile platform. Find ways to make onboarding simple and painless.

If you want to reach the widest audience, don’t assume everyone has a smart phone. 62 million smartphones were sold in the US in Q2 of 2010 according to Gartner Research. But in the same time period 264 million “dumbphones” without Web browsers or app capabilities were sold to users. If you want to reach the widest possible audience, think about how your app can be accessed via SMS or voice control. Great examples of SMS integration include Ushahidi, a platform for tracking human rights violations , and Twitter’s SMS integration.

Hear more about what Corey predicts on branding and mobile by viewing our video, Making the Most of Mobile.

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