Verbally Assisted Haptic Graph Comprehension: The Role of Taking Initiative in a Joint Activity

Statistical graphs are tools for multimodal communication in daily life settings. For visually impaired people, haptic interfaces provide perceptual access to the information provided by the graph. Haptic comprehension can be facilitated by audio and verbal assistance. We investigate the circumstances under which verbal assistance facilitates haptic comprehension of graphs. For this, we focus on cases where unaided haptic graph comprehension has limitations, such as when describing a global (rather than a local) maximum. In an experiment that employed a joint activity setting, we observed two major factors for facilitating haptic-graph comprehension by providing verbal assistance: First, the results revealed significant impact of the explorer as a dialogue initiator during the course of haptic exploration. Second, verbal assistance led to more successful graph comprehension when it was enriched by modifiers.