Using hierarchies to support non-visual access to relational diagrams

This paper describes an approach to support non-visual exploration of graphically represented information. We used a hierarchical structure to organize the information encoded in a relational diagram and designed two alternative audio-only interfaces for presenting the hierarchy, each employing different levels of verbosity. We report on an experimental study that assessed the viability of our proposed approach as well as the efficiency and learnability of each interface. Our results show that the relational information encoded in a diagram could be non-visually navigated and explored through a hierarchy, and that substituting verbal descriptions of parts of such information with nonverbal sounds significantly improve performance without compromising comprehension.