Diffscriber: Describing Visual Design Changes to Support Mixed-Ability Collaborative Presentation Authoring

Visual slide-based presentations are ubiquitous, yet slide authoring tools are largely inaccessible to people who are blind or visually impaired (BVI). When authoring presentations, the 9 BVI presenters in our formative study usually work with sighted collaborators to produce visual slides based on the text content they produce. While BVI presenters valued collaborators’ visual design skill, the collaborators often felt they could not fully review and provide feedback on the visual changes that were made. We present Diffscriber, a system that identifies and describes changes to a slide’s content, layout, and style for presentation authoring. Using our system, BVI presentation authors can efficiently review changes to their presentation by navigating either a summary of high-level changes or individual slide elements. To learn more about changes of interest, presenters can use a generated change hierarchy to navigate to lower-level change details and element styles. BVI presenters using Diffscriber were able to identify slide design changes and provide feedback more easily as compared to using only the slides alone. More broadly, Diffscriber illustrates how advances in detecting and describing visual differences can improve mixed-ability collaboration.