Towards Ubiquitous Accessibility: Capability-based Profiles and Adaptations, Delivered via the Semantic Web
Matthew Tylee Atkinson, Matthew J. Bell, Colin H. C. Machin · 2012 · Proceedings of the International Cross-Disciplinary Conference on Web Accessibility (W4A) · doi:10.1145/2207016.2207020
Summary
This paper from Loughborough University proposes using semantic web technologies (RDF and OWL) to deliver capability-based user profiles and adaptive accessibility solutions across devices and platforms. The authors argue that the current assistive technology landscape is fragmented: users struggle to find appropriate ATs, compatibility is uncertain, and profiles are device-specific rather than portable. Their approach rests on three key shifts. First, user profiles should be based on human capabilities (using WHO's International Classification of Functioning, Disability and Health — ICF) rather than machine-specific quantities like pixel depth, making profiles portable across devices. Second, rather than relying on monolithic, conspicuous assistive technologies, the system considers a broader spectrum of "adaptations" — from simple settings changes and Vanderheiden's "Micro-ATs" through to full screen readers — allowing subtle, appropriate support for people with transient or minor impairments, not just those with recognised disabilities. Third, semantic web delivery using RDF/OWL enables flexible, platform-independent storage with inference capabilities that can reason about user-adaptation matches.
Key findings
The paper compares the approach against related projects (SNAPI, CC/PP, GUIDE, GPII) and identifies that existing profiling methods tend to express profiles at the technical end of the spectrum, making them less portable to new device types. The capability-based reasoning system works by comparing the gap between capabilities required by content, device, and situation against those possessed by the user, then suggesting appropriate adaptations. Importantly, the system accounts for adaptation side-effects — for example, screen zooming reduces visible content area, creating additional motor and cognitive burden from panning. User preferences are modelled as trade-offs the user is willing to accept. The semantic profile approach enables dynamic, gradually assembled profiles rather than static questionnaire-based ones: capability estimates are passively refined from observed behaviour, out-of-date data are archived, and patterns of capability change (such as age-related decline) can be inferred to enable pre-emptive accessibility support before service loss occurs. An illustrative example shows how recording a user's fine motor capability (rather than "cannot use scroll wheel") allows the system to infer that pinch-to-zoom on an unfamiliar multi-touch terminal would also be problematic, and provide an alternative zoom widget.
Relevance
This paper anticipated many ideas that later materialised in the GPII/Morphic project and W3C's work on personalisation. The core insight — that accessibility profiles should describe human capabilities rather than device-specific settings — remains a powerful principle for modern accessibility architecture. The concept of a spectrum of adaptations from subtle settings tweaks to full ATs, rather than an all-or-nothing approach, addresses a persistent gap: many people with minor or situational impairments could benefit from small interface adjustments but would never seek out or identify with traditional assistive technology. For practitioners, the paper offers a useful framework for thinking about adaptation side-effects and trade-offs, and the argument that accessibility features should be integrated into mainstream settings rather than segregated into "Accessibility" menus remains relevant to platform design today.
Tags: adaptive interfaces · personalization · semantic web · user modeling · assistive technology · universal design · accessibility standards · user profiles
Standards referenced: ICF · ISO 24751 · CC/PP · RDF · OWL