Designing software architectures to facilitate accessible Web applications

Abstract

The Web application is increasingly a platform of choice for complex business software and online services. However, it remains a challenge to ensure that the Web application is easy, efficient, and effective for people with disabilities. Accessibility requires that users with disabilities, including those who are blind, have low vision, or have mobility impairments, are able to use the applications effectively and with a reasonable amount of effort. Although there has been important progress in recent years in describing the relationship between architecture and usability, the topic of architectural support for accessibility has not been adequately addressed. Based on our experience in designing Web applications for the United States Social Security Administration, we have begun to identify guidelines for architectures that support accessibility. This paper describes common accessibility problems encountered in Web applications and explains how architecture can help address these problems through reusable accessible objects, supplementing information in links, buttons, and labels, assisting in access to Web page visual information, handling errors, and providing time-out notification and recovery. It also discusses the critical role of architecture in supporting the best way of meeting the needs of diverse user groups: multiple dynamic views of the user interface.