Task-driven plasticity: one step forward with UbiDraw

Vanderdonckt, Jean [UCL] Calleros, J.M.G.

Task-driven plasticity refers to as the capability of a user interface to exhibit plasticity driven by the user's task, i.e. the capability of a user interface to adapt itself to various contexts of use while preserving some predefined usability properties by performing adaptivity based on some task parameters such as complexity, frequency, and criticality. The predefined usability property considered in task-driven plasticity consists of maximizing the observability of user commands in a system-initiated way driven by the ranking of different tasks and sub-tasks. In order to illustrate this concept, we developed UbiDraw, a vectorial hand drawing application that adapts its user interface by displaying, undisplaying, resizing, and relocating tool bars and icons according to the current user's task, the task frequency, or the user's preference for some task. This application is built on top of a context watcher and a set of ubiquitous widgets. The context watchers probes the context of use by monitoring how the user is carrying out her current tasks (e.g., task preference, task frequency) whose definitions are given in a run-time task model. The context watcher sends this information to the ubiquitous widgets so as to support task-driven plasticity.