Trailblazer

摘要

For blind web users, completing tasks on the web can be frustrating. Each step can require a time-consuming linear search of the current web page to find the needed interactive element or piece of information. Existing interactive help systems and the playback components of some programming-by-demonstration tools identify the needed elements of a page as they guide the user through predefined tasks, obviating the need for a linear search on each step. We introduce TrailBlazer, a system that provides an accessible, non-visual interface to guide blind users through existing how-to knowledge. A formative study indicated that participants saw the value of TrailBlazer but wanted to use it for tasks and web sites for which no existing script was available. To address this, TrailBlazer offers suggestion-based help created on-the-fly from a short, user-provided task description and an existing repository of how-to knowledge. In an evaluation on 15 tasks, the correct prediction was contained within the top 5 suggestions 75.9% of the time.