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Interfaces Supporting One-Handed Use of Small Devices

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Project description

We are developing interfaces to support one-handed use of small devices. Most cell phones already support one-handed use, but most lack touch screens and thus interaction is limited to keypad-mapped menus and directional navigation. Personal Digital Assistants (PDAs) on the other hand, do have touch sensitive displays, but are poor at supporting one-handed use for two main reasons. The first is that software interfaces for PDAs typically feature input targets that are too small for finger tip actuation, thus requiring a stylus, and two hands to use. The second reason is that the entire screen is valid for user input, which typically exceeds the extent of the thumb when held in one hand.

Our goal is to develop a single one-handed interation system for both cell phones and PDAs. A unified architecture allows us to provide users with a single interface and interaction model across devices. Our architecture uses scalable user interface techniques to allow the system to adapt to different screen sizes and aspect ratios. Univeristy of Maryland's PocketPiccolo.NET development toolkit for scalable user interface provides the underlying support for this architecture.

Much of this work has been heavily motivated by our prior work on DateLens, a space-conserving calendar for PDAs.

We have designed two alternative "shell" interfaces, which organize and manage access to system applications. Between the two interfaces we have varied the number of applications managed, the zoom technique used, and the gestural interaction model supported.


AppLens manages nine applications aranged in a 3x3 grid of notification tiles. Three fisheye zoom levels provide tiered access to application details. Users issue command gestures over the surface of the screen to move an input cursor and interact with objects under the cursor.


LaunchTile manages thirty-six applications, arranged in a 3x3 grid of nine zones, with each zone containing four notification tiles. Three pure zoom levels provide tiered access to application details. All LaunchTile input targets have been designed large enough for direct finger interaction.


Ben Bederson, Associate Professor, Computer Science
Amy Karlson, Graduate Research Assistant, Computer Science
John SanGiovanni, Microsoft Research
Aaron Clamage, Faculty Research Assistant, Computer Science

For more information or comments, please contact Amy Karlson


Karlson, A.K., B. Bederson, and J. SanGiovanni. AppLens and LaunchTile: Two Designs for One-Handed Thumb Use on Small Devices. Proceedings of the SIGCHI conference on Human Factors in Computing Systems, ACM Press (2005). Technical Report HCIL-2004-37

CHI2005 Presentation (870 KB)   AppLens Movie (17.5 MB)   LaunchTile Movie (24 MB) AppLens and LaunchTile Conference Video (16 MB) AppLens and LaunchTile Conference Video (80 MB)


This work is suported by Microsoft Research, and has been performed in collaboration with them.

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