Mobile UX Primer: Principles

Mobile UX Principles

Below are a set of user experience principles based upon writings and presentations by various mobile design experts, trying to define some core bedrock of ideas to guide tactical decision-making.

When in Rome… Leverage platform OS models, metaphors, and elements to achieve an experience consistent with user expectations for that device. For example, Android users expect “touch and hold” to call up a contextual menu of options, while “touch and hold” on iOS causes the object to “wiggle,” ready for deletion. And avoid desktop idioms such as floating windows, hover states, resizable panels, scrollbars, etc.

Balanced coherence: As appropriate for your app, balance functional and visual coherence across mobile, web, and desktop channels. Yes the functionality, capability, and visuals may vary per OS (see When in Rome…), but the experience should be intuitive and familiar when switching from one platform to another. Every pixel of the interface should add value to the user experience. Make it beautiful, and make it feel like a family.

Speak its power: Create clear, explicit, and discoverable UI controls that convey exactly what they do, like a light switch. Mobile users are often “on the go” and prefer obvious clear actions to complete tasks.

Animate to delight and orient: Leverage mobile OS animations and transitions to show the placement of hidden controls, suggest orientation/navigation/location, and add delight. For example, upon first launch, gently animate a hidden search field to visually cue the user to its placement.

Pivot, snack, bursts: Support “snacking” by enabling users to pivot through tasks and information in quick bursts. Remember, the user is not chained to a desk for hours. They are often in a state of “constant partial attention,” multitasking across physical and virtual contexts, sometimes one-handed while doing something else.

Edit ruthlessly: Don’t cram an entire desktop app into a phone or tablet. Focus, prioritize, and simplify to what matters most. This includes verbiage, imagery, features, buttons, icons, and especially menu commands, which should be exposed in clear visual ways.

Beware “fat finger”: Provide easy recovery from accidental taps and keep critical controls separated. Ask yourself: How can a mobile user still make use of this app with one hand while holding a coffee cup?

Minimize typing, maximize defaults: Despite auto-suggest, typing on a phone is difficult. Use defaults if possible, or carry-over from previous saved sessions/states, etc.

Think about the ecosystem, not just this device: Don’t design a mobile app in isolation. Keep in mind the ecosystem of functionality; your app should express a unified look and feel across multiple channels and devices. This is especially true if designing for multiple mobile OS platforms.

Focus on being useful, straight-forward…and fun! Don’t forget the cool factor of using mobile devices and apps. It counts towards your product’s brand perception, especially in over-crowded app stores. Users will reject your app brutally and quickly!

For your mobile UI, always ask…
– Can users make sense of it…quickly?
– Does each screen speak its power?
– Can I simplify this?
– Is this intuitive?