Screen Readers Cannot See: Ontology Based Semantic Annotation for Visually Impaired Web Travellers

Travelling upon the Web is difficult for visually impaired users since the Web pages are designed for visual interaction. Visually impaired users usually use screen readers to access the Web in audio. However, unlike sighted users, screen readers cannot see the implicit structural and navigational knowledge encoded within the visual presentation of Web pages. Therefore, in a visually impaired user’s environment, objects that support travel are missing or inaccessible. Our approach to remedy this is to annotate pages with an ontology, the Travel Ontology, that aims to encapsulate rich structural and navigational knowledge about these objects. We use Semantic Web technologies to make such knowledge explicit and computationally accessible. Our semi-automated tool, Dante identifies travel objects on Web pages, annotates them appropriately with the Travel Ontology and uses this to transform the pages to enhance the travel support. Thus Dante uses the Travel Ontology to enhance the travel experience of visually impaired users. This paper introduces the Travel Ontology, the annotation pipeline used in the annotation part of Dante and some transformation scenarios to illustrate how the annotations are used to guide the transformation of Web pages.