PowerUp: An Accessible Virtual World
Shari Trewin, Vicki L. Hanson, Mark R. Laff, Anna Cavender · 2008 · Proceedings of the 10th International ACM SIGACCESS Conference on Computers and Accessibility (Assets '08) · doi:10.1145/1414471.1414504
Summary
This paper describes the design and validation of accessibility features for PowerUp, an IBM-developed multiplayer 3D virtual world educational game aimed at middle school students. The researchers were tasked with making the game usable by players with visual, hearing, cognitive, and physical disabilities. The work began with requirements gathering through an online survey of 25 disabled gamers across five disability groups (blind, low vision, dexterity impairment, deaf/hard of hearing, and cognitive disability), supplemented by consultation with a Lighthouse International orientation and mobility instructor and the team's own web accessibility expertise. The resulting accessibility features addressed both 2D interface elements (GUIs, heads-up displays) and the 3D virtual world itself. For 2D elements, features included customisable font size and colour, keyboard-only and mouse-only navigation of all menus, self-voicing text-to-speech output built into the game (not requiring external screen readers), and on-screen captions for audio. For the 3D world, the team developed novel navigation tools: a "find" command that scans the view for objects and reports their name, distance, and direction; a "controlled walk" function that automatically guides the avatar toward a target while stopping at obstacles; "look" commands that describe the scene in words; and environmental sound effects including varying footstep sounds for ascending/descending terrain and distinct bump sounds for different objects.
Key findings
Validation testing with seven legally blind teenagers (aged 13-15) at Lighthouse International across three 90-minute sessions demonstrated that the accessibility features were effective. All participants were able to independently navigate GUI screens, log on, customise avatars, teleport to missions, and build wind turbines. Six of seven used the graphical display alongside audio tools, and all found in-world contrast and lighting sufficient. The find and controlled walk commands proved particularly valuable — five found find useful for locating and locking onto moving objects, and five used controlled walk for following other players. Participants preferred speech feedback over non-speech sound effects "because it is easier to understand." The iterative design process was critical: after sessions one and two, the team expanded spoken descriptions to include gaze direction and distance-grouped objects, added bump sounds, modified controlled walk to stop at cliffs, and adjusted the find/look detection range. The greatest remaining difficulty was large-scale navigation — finding specific far-off locations and team members — which a planned map feature was expected to address. Notably, no two participants used the same combination of settings and tools, underscoring the importance of providing flexible, configurable accessibility options.
Relevance
This paper makes a compelling case that 3D virtual worlds can be made accessible to people with a wide range of disabilities, and that the barriers are more about available development time and resources than inherent limitations of the medium. The novel navigation tools — find, controlled walk, and look commands — represent genuinely innovative approaches to non-visual navigation in 3D spaces that go beyond simple teleportation. The survey data provide valuable first-person accounts of how disabled gamers experience and work around barriers, organised by disability type with concrete design implications. For accessibility practitioners, the paper's most important argument is that these features should be built into virtual world engines rather than retrofitted into individual games, establishing standard accessibility controls that all developers and users can rely on. As virtual and augmented reality technologies become more prevalent in education, training, remote work, and social interaction, the principles and patterns established here — self-voicing, audio scene description, assisted navigation, configurable preferences — remain directly applicable to modern XR accessibility challenges.
Tags: game accessibility · virtual reality · visual impairment · blindness · cognitive accessibility · motor disability · deaf and hard of hearing · inclusive design · navigation · self-voicing interface · sonification