Sistema ETD

banca dati delle tesi e dissertazioni accademiche elettroniche


Tesi etd-04242012-121149

Tipo di tesi
Tesi di dottorato di ricerca
Web Accessibility and Collaboration to Support Learning for Blind People
Settore scientifico disciplinare
Corso di studi
tutor Dott.ssa Buzzi, Maria Claudia
tutor Dott.ssa Buzzi, Marina
tutor Dott. Bechini, Alessio
Parole chiave
  • screen reader
  • learning
  • collaboration
  • blind
  • accessibility
Data inizio appello
Riassunto analitico
The increasing spread of the Information Technology (IT) and multimedia devices, along with the impressive growth of Web 2.0 applications (wikis, social networks, blogs, etc.), have radically changed communication and ways of acquiring information and knowledge. Collaboration between individuals in combination with an active, enriched sensorial experience for the user, have produced new paradigms for learning and teaching, compared to the classic passive methods of the past. Unfortunately, enriched and multimedia applications are usually designed for the sighted, and are often ineffective for blind users, who typically interact with a computer by screen reader via vocal synthesizer and a keyboard. This thesis investigates the design of accessible and usable Web e-Learning tools and specifically collaborative environments to support learning for blind people, overcoming their difficulties during the interaction. After a description of the main difficulties encountered by blind users when interacting via screen reader, and the basic principles for creating accessible interfaces, the design, implementation and test of several prototypes for improving the learning experience of blind people will be described.

Specifically, a prototype of a Web tool for transforming digital documents into structured audio podcasts (according to the document structure) that has been designed and developed, will be presented. The structured audio podcasts (one mp3 file for each document section) are downloadable via Web and loadable on an mp3 player. Structured podcasts represent an effective tool for blind students who wish to explore document contents during the critical phase of surveying educational material. User tests of the system performed with blind users have highlighted their appreciation for structured audio podcasts compared to a time division method (e.g., 5 minutes per podcast). Furthermore, the W3C WAI-ARIA-based system interfaces have been evaluated successfully by blind users, who considered them easy to navigate and explore. The system provides other facilities for audio emphasizing some visual information embedded in the document (bold, italics, tables, etc.). The system also generates special audio formats (i.e., Rockbox and DAISY) to facilitate exploitation of educational material on a portable audio device.

Furthermore, the new cooperative learning paradigm shows how active participation and collaborative interaction are fundamental for improving the learning experience. However, e-learning collaborative environments are complex and rich in dynamic content and therefore complex to access for a sightless person. Therefore, we investigated accessibility and usability via screen reader of Web collaborative editing tools, selecting Google Docs as a case study. A modified version of the Google Docs interfaces designed and implemented to fix detected accessibility problems will be presented. Moreover, an accessibility inspection of the main collaborative functions of Google Docs was performed, also considering the importance of the awareness. The analysis of main groupware features of typical collaborative tools and the experience on Google Docs have provided us with interesting indications regarding the design of accessible and usable interfaces for cooperative tools.