TextSL: a screen reader accessible interface for second life
Bugra Oktay, Eelke Folmer · 2010 · Proceedings of the 2010 International Cross Disciplinary Conference on Web Accessibility (W4A) · doi:10.1145/1805986.1806017
Summary
This paper presents TextSL, a text-based command interface for Second Life that enables visually impaired users to explore and interact with the virtual world using a screen reader (JAWS). Inspired by multi-user dungeon (MUD) text adventure games like Zork — the predecessors of modern virtual worlds — TextSL replaces Second Life's visual 3D viewer with a command-based interface built on the libsecondlife library. The system communicates directly with Second Life servers without performing any graphical rendering, making it lightweight enough to run on low-end machines. Users issue natural language commands across three functional areas: exploration (move, fly, follow, teleport, describe surroundings, query object locations), communication (public say, private whisper, mute), and interaction (sit on or touch objects). The interpreter supports prepositions and adjectives, allowing commands like "sit on the chair" or "move to the chair." A key design choice was to leverage the user's own screen reader rather than built-in speech synthesis, since visually impaired users typically customize their screen reader's speed, tone, and other preferences.
Key findings
A user study with 8 screen reader users confirmed that TextSL allows blind users to explore Second Life, interact with objects, and communicate with other avatars with the same success rates as sighted users using the standard visual viewer. Communication efficiency was equivalent, which is significant since social interaction is the most common activity in virtual worlds. However, exploration and interaction were inherently slower due to the iterative nature of text-based querying. The research identified two fundamental barriers to virtual world accessibility. First, object density: virtual worlds are so densely populated that environment queries produce overwhelming amounts of information. TextSL addresses this with a summarizer that culls non-descriptively named objects, prioritizes remaining objects by name descriptiveness and distance, and groups objects into sets that users can drill into iteratively. Second, metadata absence: content creators assume visual users and typically assign meaningless names like "object," "shapeblock," or "BuiltUsingSkidzPrimz" — useless for screen reader users. TextSL also implements collision-free navigation using the A* pathfinding algorithm, automatically plotting safe routes and teleporting users who fail to arrive within estimated time limits.
Relevance
TextSL demonstrates a practical approach to virtual world accessibility by drawing on text adventure gaming heritage — a medium that was inherently accessible to blind users before graphical interfaces became dominant. The MUD-inspired command interface represents a philosophically different approach from IBM's GUI widget abstraction (presented at the same conference): rather than translating 3D space into accessible GUI elements, TextSL returns to the text paradigm that blind users already know well. The two barriers identified — object density causing information overload and pervasive lack of object metadata — are fundamental structural problems that apply to any virtual environment accessibility effort and remain unsolved in modern VR platforms. The A* pathfinding for collision-free navigation is an elegant solution that removes a significant burden from blind users navigating object-dense spaces. For accessibility practitioners working on metaverse or spatial computing platforms today, this paper provides evidence that text/command interfaces can achieve functional parity with visual interfaces for social interaction tasks, even if spatial exploration remains slower. The gamification approach to crowdsourcing object labels (mentioned as future work) anticipates solutions like games with a purpose for accessibility metadata.
Tags: virtual worlds · screen readers · visual impairment · blindness · text-based interface · command-line interface · Second Life · game accessibility