Little Springs Design. 2001 – 2010.

Mobile phones are very portable. They fit in pockets and purses, and many users are never without their phone. This fact has numerous implications for the design of the device, which I summarized in my earlier post on The Carry Principle.

It also has implications for application and web site design. Consider the first implication: the device is small.

A small device with a small screen will force single-window interaction. The user can be using exactly one application at a time. An interrupted application is truly interrupted unless the device returns focus to the abandoned application. Most devices are good at managing incoming messages during application use, but bad at launching other applications or calls while maintaining application status.

In particular, some browsers return the user to the home page upon each launch; these browsers cause the user to lose track of what was happening before the interruption. The interruption problem also exists for Java and other platforms. The time to launch the application can reach thirty seconds, so an exited application reduces the likelihood of continued application use.

The single-window interaction also causes challenges in accessing information outside the application. Just as the phone book or calendar needs to be available during a voice call, movie information might be useful for a chat session.

All of this drives to a pair of conclusions:

1. Device manufacturers need to manage multiple applications better. Specifically, there needs to be access to the main menu at all times, application state needs to be saved for all applications, launch times should be reduced, and applications should (normally) be launched to where they were left.
2. Applications should provide access to information resources that might be needed to successfully use the application.

PalmOS, Windows Mobile, and Symbian do #1 with varying levels of success. PalmOS in particular is good at maintaining application state, but bad at helping the user find the most recently used application. OEM devices are particularly bad, and third party browsers are only somewhat integrated into the device.

Applications are bad at achieving #2. This is not entirely their fault, of course, with the restrictions on application size and the need to ensure that an information source is available. Regardless, mobile users deserve to have similar access to disparate sources of information as do desktop users.

This entry was posted on Friday, July 7th, 2006 at 9:53 am and is filed under Design, Design Tips, Devices, Mobile web. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.