Opening up access to online documents using essentiality tracks
Matthew T. Atkinson, Jatinder Dhiensa, Colin H. C. Machin · 2006 · Proceedings of the 2006 International Cross-Disciplinary Workshop on Web Accessibility (W4A) · doi:10.1145/1133219.1133222
Summary
This paper from Loughborough University presents extensions to the "essentiality and proficiency" approach for improving document accessibility and usability. The core concept is that web page content has varying levels of importance for different users, and authors can assign essentiality ratings (1-10) to content sections. A proxy-based tool then filters and transforms content based on user preferences and device capabilities, delivering only the information relevant to each user at an appropriate proficiency level. The authors extend this system in two significant ways: first, by applying it to DocBook XML documents (a widely-used technical documentation format), enabling organizations to maintain a single source document that can be automatically rendered into accessible formats including HTML, PDF, RTF, and potentially Braille. Second, they introduce "essentiality tracks" — a mechanism for marking up content importance differently for different user roles (e.g., managers, developers, testers). This allows a single corporate document to serve multiple audiences, with each reader seeing content filtered to their role and preferred level of detail. The paper also addresses practical challenges such as context preservation when filtering nested content, and proposes track coordination features including grouping and relationship rules.
Key findings
The research demonstrates that essentiality-based filtering can be practically implemented within DocBook XML by extending its DTD, leveraging DocBook's existing separation of content from presentation and its XSLT transformation pipeline. The authors cite the UK Disability Rights Commission finding that accessible websites are 35% easier to use for everyone, establishing that accessibility improvements benefit all users. They identify three core barriers to web access: information exclusion (lack of access or prohibitive assistive technology costs), standards compliance not guaranteeing usability, and information overload. The essentiality tracks extension addresses the scalability limitation of the original single-track system, enabling long documents aimed at multiple roles to be effectively filtered. The system avoids common proxy-service pitfalls because organizations control the entire standards and transformation chain. Informal testing with the AGRIP accessible gaming community (whose users are predominantly blind) yielded positive feedback on both accessibility and general productivity improvements. The authors also developed a Firefox plugin providing a GUI for authors to mark up essentiality levels without editing source code directly.
Relevance
This paper presents an early and thoughtful approach to a problem that persists in digital accessibility: how to deliver the right amount of information to diverse users without maintaining multiple document versions. The concept of content essentiality — letting users control how much detail they receive based on their role and needs — anticipates modern approaches to progressive disclosure and adaptive content. For practitioners, the key takeaway is that accessible document design should consider not just format and presentation but also information architecture and content relevance. The integration with DocBook XML demonstrates how accessibility can be built into existing documentation workflows rather than retrofitted. While the specific technology (DocBook, XSLT proxies) has been largely superseded, the underlying principles of role-based content filtering and single-source accessible publishing remain highly relevant to modern content management systems and structured authoring.
Tags: document accessibility · content filtering · XML · universal design · information overload · assistive technology
Standards referenced: WCAG 1.0 · DocBook XML