Darren Lunn

Accessibility commons: a metadata infrastructure for web accessibility

Research projects, assistive technology, and individuals all create metadata in order to improve Web accessibility for visually impaired users. However, since these projects are disconnected from one another, this metadata is isolated in separate tools, stored in disparate repositories, and represented in incompatible formats. Web accessibility could be greatly improved if these individual contributions were merged. An integration method will serve as the bridge between future academic research projects and end users, enabling new technologies to reach end users more quickly. Therefore we introduce Accessibility Commons, a common infrastructure to integrate, store, and share metadata designed to improve Web accessibility. We explore existing tools to show how the metadata that they produce could be integrated into this common infrastructure, we present the design decisions made in order to help ensure that our common repository will remain relevant in the future as new metadata is developed, and we discuss how the common infrastructure component facilitates our broader social approach to improving accessibility.

Combining SADIe and AxsJAX to improve the accessibility of web content

The advent of Web 2.0 technologies has allowed once static Web documents to be transformed into online interactive applications. To facilitate the accessibility of this dynamic content, Google have developed the AxsJAX framework that can insert Accessible Rich Internet Applications (ARIA) statements into the content dynamically. Such statements allow assistive technologies to interact with dynamic content and make it accessible to users. SADIe is an approach that uses semantic annotations of a Websites Cascading Style Sheet (CSS) to drive a transformation process that can improve access to Web pages for visually impaired users who use a screen reader. Previously SADIe transcoded static pages by refactoring the content into a format more suited to the sequential audio output of a screen reader. In this paper we present a prototype SADIe transcoder that uses CSS annotations to generate AxsJAX framework code and insert it into Web pages. Such an approach allows users to access static content using a consistent set of key presses in a manner akin to an online application. This demonstrates the flexibility of the SADIe approach as the same annotations can be used to generate an alternative transcoding format. It also supports the use of SADIe as a lightweight method for allowing Web designers to make use of AxsJAX without requiring knowledge of the underlying AxsJAX technologies.

Identifying Behavioral Strategies of Visually Impaired Users to Improve Access to Web Content

The World Wide Web is a predominantly visual media for presenting and disseminating information. As such, visually impaired users, who access content through audio interaction, are hindered as the Web is not designed with their needs in mind. To compensate for this, visually impaired users develop behavioral strategies to cope when access to the content becomes challenging. While tools exist to aid visually impaired users in accessing the Web, they tend to focus on adapting content to meet the needs of the device rather than the user. Therefore, to further improve Web access an understanding of the behavioral strategies users employ is required. To achieve this, studies of eleven visually impaired Web users were conducted. The data from these sessions were analyzed to develop a framework for identifying strategies that users may employ when they face difficulties accessing the content. Using data for twenty visually impaired users obtained from an independent study, the framework was validated and shown to be flexible and accurate enough to be applicable to multiple data sources. An analysis of the coping strategies identified from the framework revealed six abstract patterns of coping. These patterns were used as the basis for developing behavior-driven transcoding that transformed static Web documents into interactive content by allowing users to navigate between key elements of the page through a consistent set of key presses. Results obtained from a user evaluation of the transcoding support the use of behavior-driven transcoding as a mechanism for improving access to Web content when compared to existing transcoding techniques. This result allows the coping strategies framework to be used as a foundation for further understanding of the strategies visually impaired users employ on Web sites and the transformations required to allow the Web to be accessible to those users.

Widget Identification: A High-Level Approach to Accessibility

The Web 2.0 sees once static pages evolve into hybrid applications, and content that was previously simple, now becoming increasingly complicated due to the many updating components located throughout the page. While beneficial for some users, these components (widgets) are often complex and will lead to confusion and frustration for others, notably those for whom accessibility is already an issue. While users and developers often perceive widgets as complete components (a Slideshow, or an Auto Suggest List), they are in-fact heterogeneous collections of code, and are therefore hard to computationally identify. Identification is critical if we wish to reverse engineer inaccessible widgets or ‘inject’ missing ‘WAI-ARIA’ into ‘RIAs’. In this case, we introduce a technique that analyses the code associated with a Web page to identify widgets using combinations of code constructs which enable uniquely identification. We go on to technically evaluate our approach with the most difficult widgets to distinguish between—Slideshows and Carousels—and then describe two prototype applications for visually impaired and older users by means of example.

SADIe: semantic annotation for accessibility

Visually impaired users are hindered in their efforts to access the largest repository of electronic information in the world – the World Wide Web (Web). The web is visually-centric with regard to presentation and information order / layout, this can (and does) hinder users who need presentation-agnostic access to information. Transcoding can help to make information more accessible via a restructuring of pages. We describe an approach based on annotation of web pages, encoding semantic information that can then be used by tools in order to manipulate and present web pages in a form that provides easier access to content. Annotations are made directly to style sheet information, allowing the annotation of large numbers of similar pages with little effort.

Using galvanic skin response measures to identify areas of frustration for older web 2.0 users

The World Wide Web (Web) is changing. The much vaunted Web 2.0 sees once static pages evolving into hybrid applications. Content that was once simple is now becoming increasingly complicated due to the many updating components located throughout the page. The information overload and visual complexity of such components is significant. This increased complexity can produce lower performance and higher levels of stress and frustration which negatively effect the user. In previous work we have shown how galvanic skin response (GSR) measurements, collected in tandem with eye-tracking data, can be used as a method for determining how stressed users become when interacting with content. The results of that study demonstrated that when used appropriately, the presence of Web 2.0 content can reduce GSR measurements and be of benefit to users. In this work, the previous study was repeated with twenty-three older Web users to establish if similar patterns of interaction could be established. The results reveal that while older participants made use of dynamic content, unlike previous participants, they were a non-homogenous group with a large variance in the GSR measurements. We assert that a cause of this is hesitancy and therefore developing techniques to reduce hesitancy will benefit older users when interacting with Web 2.0 content.

SADIe:: transcoding based on CSS

Visually impaired users are hindered in their efforts to access the World Wide Web (Web) because their information and presentation requirements are different from those of a sighted user. These requirements can become problems as the Web becomes ever more visually centric with regard to presentation and information order / layout, this can (and does) hinder users who need presentationagnostic access to information. Finding semantic information already encoded directly into pages can help to alleviate these problems and support users who wish to understand the meaning as opposed to the presentation and order of the information. Our solution, Structural-Semantics for Accessibility and Device Independence (SADIe) involves building ontologies of Cascading Sytle-Sheets (CSS) and using those ontologies to transform Web pages.

A user evaluation of the SADIe transcoder

The World Wide Web (Web) is a visually complex, dynamic, multimedia system that can be inaccessible to people with visual impairments. SADIe addresses this problem by using Semantic Web technologies to explicate implicit visual structures through a combination of an upper and lower ontology. This is then used to apply transcoding to a range of Websites. This paper describes a user evaluation that was performed using the SADIe system. Four users were presented with a series of Web pages, some having been adapted using SADIes transcoding functionality and others retaining in their original state. The results of the evaluation showed that providing answers to a fact based question could be achieved more quickly when the information on the page was exposed via SADIes transcoding. The data obtained during the experiment was analysed and shown to be statistically significant. This suggests that the transcoding techniques offered by SADIe can assist visually impaired users accessing content on the Web.

The SADIe transcoding platform

The World Wide Web (Web) is a visually complex, dynamic, multimedia system that can be inaccessible to people with visual impairments. SADIe addresses this problem by using Semantic Web technologies to explicate implicit visual structures through a combination of an upper and lower ontology. By identifying elements within the Web page, in addition to the role that those elements play, accurate transcoding can be applied to a diverse range of Websites.

End User Evaluations

As new technologies emerge, and Web sites become increasingly sophisticated, ensuring they remain accessible to disabled and small-screen users is a major challenge. While guidelines and automated evaluation tools are useful for informing some aspects of Web site design, numerous studies have demonstrated that they provide no guarantee that the site is genuinely accessible. The only reliable way to evaluate the accessibility of a site is to study the intended users interacting with it. This chapter outlines the processes that can be used throughout the design life cycle to ensure Web accessibility, describing their strengths and weaknesses, and discussing the practical and ethical considerations that they entail. The chapter also considers an important emerging trend in user evaluations: combining data from studies of “standard” Web use with data describing existing accessibility issues, to drive accessibility solutions forward.