Interactive SIGHT: textual access to simple bar charts
Information graphics, such as bar charts and line graphs, are an important component of many articles from popular media. The majority of such graphics have an intention (a high-level message) to communicate to the graph viewer. Since the intended message of a graphic is often not repeated in the accompanying text, graphics together with the textual segments contribute to the overall purpose of an article and cannot be ignored. Unfortunately, these visual displays are provided in a format which is not readily accessible to everyone. For example, individuals with sight impairments who use screen readers to listen to documents have limited access to the graphics. This article presents a new accessibility tool, the Interactive SIGHT (Summarizing Information GrapHics Textually) system, that is intended to enable visually impaired users to access the knowledge that one would gain from viewing information graphics found on the web. The current system, which is implemented as a browser extension that works on simple bar charts, can be invoked by a user via a keystroke combination while navigating the web. Once launched, Interactive SIGHT first provides a brief summary that conveys the underlying intention of a bar chart along with the chart's most significant and salient features, and then produces history-aware follow-up responses to provide further information about the chart upon request from the user. We present two user studies that were conducted with sighted and visually impaired users to determine how effective the initial summary and follow-up responses are in conveying the informational content of bar charts, and to evaluate how easy it is to use the system interface. The evaluation results are promising and indicate that the system responses are well-structured and enable visually impaired users to answer key questions about bar charts in an easy-to-use manner. Post-experimental interviews revealed that visually impaired participants were very satisfied with the system offering different options to access the content of a chart to meet their specific needs and that they would use Interactive SIGHT if it was publicly available so as not to have to ignore graphics on the web. Being a language based assistive technology designed to compensate for the lack of sight, our work paves the road for a stronger acceptance of natural language interfaces to graph interpretation that we believe will be of great benefit to the visually impaired community.
accessibility information graphics visual impairments assistive technology graph summarization