PPD: Non-visual Browsing of the World Wide Web: Tables, Frames & Forms

越来越多的教育材料被放到互联网上。大学教师通常在万维网（WWW）上发布课程作业、教学大纲和其他与课程相关的信息。这种做法使视力正常的学生可以使用这些材料，但除非这些材料是普遍可访问的，否则对视障学生来说可能是一种障碍。教学材料普遍可及性的基本前提是，课程应包括替代方案，以确保具有不同背景、学习风格、能力和残疾的学生和教师能够在广泛不同的学习环境中可及并适用。尽管最近出现了诸如万维网联盟的网络无障碍倡议（W3C WAI）和改进的软件工具的可用性，例如盲人计算机用户使用的屏幕阅读器，但是在普遍无障碍方面仍然存在许多问题。这些工具不能处理WWW的许多复杂特性，例如表、表单和基于框架的Web页面。这个项目将研究开发技术和工具，使视障学生更容易访问网页。特别是，研究工作将导向开发技术，使网页上的基于框架的材料、表格和表单可访问。这些技术将在一个原型软件工具中实现。该方法基于解析和分析构成页面的HTML结构（包含表、表单、框架等），以生成基于树的结构表示。新开发的工具将导航结构表示并产生有意义的输出，如音频和语音。将特别注意表格的表示，因为表格信息是最难向盲人传达的。这主要是由于表中隐式的结构信息在大多数屏幕阅读器线性读出时丢失。将寻求来自web页面作者（例如课程讲师）的输入，以便能够传达这种结构信息。在计划的方法中，要传达的结构信息（或理解表的提示）被形式化为层次结构树。将设计一个单独的图形工具，以交互方式允许页面作者生成这个层次结构树。层次结构树将用于适当地解释表示表的HTML结构，从而为视障用户提供更好的可访问性。将为包含框架的页面开发类似的方法。要开发的工具将采用基于编程语言语义的技术，因为解释任务需要为HTML代码分配适当的含义。现代解析、语言处理和编译技术将进一步帮助开发这些工具。许多人机交互（HCI）的问题，出现在盲人用户的背景下也将进行研究。最后，将对这些工具进行彻底的评估，这些评估的结果将用于使新工具更易于使用。

An increasing amount of educational material is being placed on the Internet. University instructors commonly distribute course assignments, syllabi, and other course-related information on the World Wide Web (WWW). This practice makes the material accessible to sighted students, but it may be an impediment to visually impaired students unless the material is universally accessible. The basic premise of universal accessibility of instructional materials is that a curriculum should include alternatives to ensure that it is accessible and applicable to students and teachers with different backgrounds, learning styles, abilities, and disabilities in widely varied learning contexts. In spite of recent initiatives such as the World Wide Web Consortium's Web Accessibility Initiative (W3C WAI) and availability of improved software tools such as screen readers used by blind computer users, many problems remain with respect to universal accessibility. These tools cannot handle many of the complex features of the WWW such as tables, forms, and frame-based Web pages. This project will perform research on developing techniques and tools that will make Web pages more accessible to visually impaired students. In particular, research efforts will be directed toward developing techniques to make frame-based materials, tables, and forms found on Web-pages accessible. These techniques will be implemented in a prototype software tool. The approach is based on parsing and analyzing the HTML structures that constitute a page (containing tables, forms, frames, etc.) to produce tree-based structural representations. The newly developed tool will navigate the structural representation and produce meaningful output such as audio and speech. Particular attention will be paid to representing tables since tabular information is the hardest to convey to a blind person. This is primarily caused by the structural information that is implicit in a table that is lost when it is read aloud linearly as is done by most screen readers. Input from the Web-page author (such as a course instructor) will be sought so that this structural information can be conveyed. The structural information (or hints for comprehending the table) to be conveyed is formalized as a hierarchy tree in the planned approach. A separate graphical tool will be designed that will interactively allow the page author to produce this hierarchy tree. The hierarchy tree will be employed to appropriately interpret the HTML structures representing tables to provide improved accessibility to visually-impaired users. A similar approach will be developed for pages containing frames. The tools to be developed will employ programming language semantics-based techniques, as the task of interpretation requires assigning appropriate meaning to the HTML code. Modern parsing, language processing, and compilation technology will further aid in the development of these tools. Many of the Human Computer Interaction (HCI) issues that arise in the context of blind users will be researched as well. Finally, these tools will be thoroughly evaluated, and the results of these evaluations will be used to make the new tools even more accessible.