Multimodal feedback for tilt controlled speed dependent automatic zooming
Speed Dependent Automatic Zooming proposed by Igarashi and Hinckley is a powerful tool for document navigation on mobile devices. We show that browsing and targeting can be facilitated by using a model-based sonification approach to generate audio feedback about document structure, in a tilt-controlled SDAZ interface. We implemented this system for a text browser on a Pocket PC instrumented with an accelerometer and headset, and found that audio feedback provided valuable information, supporting intermittent interaction, i.e. allowing movement-based interaction techniques to continue while the user is simultaneously involved with other tasks. This was demonstrated by a blindfolded user successfully locating specified elements in a text file.