Developing an understanding of the nature of accessibility and usability problems blind students face in web-enhanced instruction environments

摘要: The central premise of this research is that blind and visually impaired (BVI) people cannot use the Internet effectively due to accessibility usability problems. Use indispensable in today's education system relies on Web-enhanced instruction (WEI). Therefore, BVI students participate WEI. Extant literature recognizes non-visual Web interaction inherently challenging. However, it does not explain where, how why face problems performing academic tasks This knowledge necessary adequately inform development interventions improve functional outcomes purpose doctoral understand nature WEI environments. It adopts a novel user-centered, task-oriented, cognitive approach develop an in-depth, contextually-situated, observational experiential these context experience under investigation online exam over typical course management system. Research design qualitative field study involves multimethod evaluation environment. core component students' assessment triangulated through assessments made by WCAG (Web Content Accessibility Guidelines) developers. student employs integrated problem solving model, combination with verbal protocol analysis, identify completing exam. automated testing textual analysis interface objects violate standards characterizes problem. developer open-ended interviews source Results show environment consisted innumerable violated WCAG's usability. participants faced many posed significant challenges These fall into six major types as described below: 1. Confusion while navigating across its frame-based page structure without unique frame names; 2. Susceptibility submitting incomplete work when new question provide location contextual information; 3. Difficulty understanding submit selection controls for multiple option questions lack consistent keyboard navigation procedure; 4. Inability negotiate security information pop-up uses alert dialogue box; 5. Ambiguity essay-type meaningful labels objects, including text area formatting toolbar; 6. Vulnerability losing Backspace behaves browser's Back button inside area. contributes three ways. fills gap about interactions tasks. kind determine requirements Another contribution set mental model representations explicate thought processes students. Such are useful developing user more accessible usable sites. A third task-based, multi-method evaluate