  While audio description (AD) is the standard approach for making videos
accessible to blind and low vision (BLV) people, existing AD guidelines do not
consider BLV users' varied preferences across viewing scenarios. These
scenarios range from how-to videos on YouTube, where users seek to learn new
skills, to historical dramas on Netflix, where a user's goal is entertainment.
Additionally, the increase in video watching on mobile devices provides an
opportunity to integrate nonverbal output modalities (e.g., audio cues, tactile
elements, and visual enhancements). Through a formative survey and 15
semi-structured interviews, we identified BLV people's video accessibility
preferences across diverse scenarios. For example, participants valued action
and equipment details for how-to videos, tactile graphics for learning
scenarios, and 3D models for fantastical content. We define a six-dimensional
video accessibility design space to guide future innovation and discuss how to
move from "one-size-fits-all" paradigms to scenario-specific approaches.
