ACM Transactions on Computer-Human Interaction
Special Issue on Computers and Accessibility
Vol 14, No. 3 - 2007

Table of Contents:

1. Introduction

The Web has become pervasive in our society, with people using the Web for
personal communication, research, company intranets, online purchasing,
entertainment, and more. For many people, however, access to this information
is not a given. Individuals with various disabilities including visual,
physical, hearing, and cognitive impairments, often experience difficulties
using the Web. While the W3C has created guidelines with the goal of making
Web sites accessible, research has confirmed that adherence to these
guidelines does not necessarily result in a site that is easily used by
persons with disabilities. The goal of this special issue is to collect a set
of articles which will help HCI professionals better understand how they can
maximize the accessibility and usability of Web sites. More specifically, our
goal was to collect articles that discuss either (1) empirical studies of
issues related to the usability ofWeb sites by persons with disabilities or
(2) technologies, tools or methods for easingWeb access for persons with
disabilities. Given the significant challenges involved in making the Web
fully accessible, the articles presented in this special issue should be
viewed as providing insights into a small subset of the relevant research. 


2. Web Accessibility for Individuals with Cognitive Deficits: A Comaprison
   Study between an Existing Commercial Web and Its Cognitively Accessible
   Equivalent

Tim Berners-Lee claimed in 2001 that "the power of the Web is in its
universality. Access by everyone regardless of disability is an essential
aspect". A considerable amount of work has been done to make the web
accessible to those with sensory or motor disability, with an increasing
number of government and enterprise intranet webs being "accessible", and
also with some consortiums and groups seriously approaching this commitment.
Some authors, such as Harrysson, have already highlighted the need for a
cognitively accessible web. However, in spite of good intentions, there has
been little work to date that has tackled this task. At least until now, the
existing WAI and NI4 recommendations about cognitive disability are extremely
difficult (if not impossible) to test, as they are only general
recommendations. This article explains an alternative Web that has been
constructed and tested on a sample of participants with cognitive
disabilities (N = 20) with positive results encouraging us to dedicate
more effort to fine tune their requirements regarding specific cognitive
deficits and automating the process of creating and testing cognitively
accessible web content. This alternative web implies the use of a simplified
web browser and an adequate web design. Discussion of the need to have
several levels of cognitive accessibility, equivalent (although not
identical) content for this collective and the need for testable protocols of
accessibility that support these people's needs is also included. This
article finishes with conclusions about the potential impact of accessible
pages in the daily life of people suffering from cognitive deficits,
outlining the features to be considered within a user profile specification
that support cognitive difficulties and with reflections about the
suitability of Semantic Web Technologies for future developments in this
field. 


3. Analysis of Navigability of Web Applications for Improving Blind Usability

Various accessibility activities are improving blind access to the
increasingly indispensable WWW. These approaches use various metrics to
measure the Web's accessibility. "Ease of navigation" (navigability) is one
of the crucial factors for blind usability, especially for complicated
webpages used in portals and online shopping sites. However, it is difficult
for automatic checking tools to evaluate the navigation capabilities even for
a single webpage. Navigability issues for complete Web applications are still
far beyond their capabilities. 

This study aims at obtaining quantitative results about the current
accessibility status of real world Web applications, and analyzes real users'
behavior on such websites. In Study 1, an automatic analysis method for
webpage navigability is introduced, and then a broad survey using this method
for 30 international online shopping sites is described. The next study
(Study 2) focuses on a fine-grained analysis of real users' behavior on some
of these online shopping sites. We modified a voice browser to record each
user's actions and the information presented to that user. We conducted user
testing on existing sites with this tool. We also developed an analysis and
visualization method for the recorded information. The results showed us that
users strongly depend on scanning navigation instead of logical navigation. A
landmark-oriented navigation model was proposed based on the results.
Finally, we discuss future possibilities for improving navigability,
including proposals for voice browsers. 


4. Evaluating DANTE: Semantic Transcoding for Visually Disabled Users

The importance of the World Wide Web for information dissemination is
indisputable. However, the dominance of visual design on the Web leaves
visually disabled people at a disadvantage. Although assistive technologies,
such as screen readers, usually provide basic access to information, the
richness of the Web experience is still often lost. In particular, traversing
the Web becomes a complicated task since the richness of visual objects
presented to their sighted counterparts are neither appropriate nor
accessible to visually disabled users. To address this problem, we have
proposed an approach called Dante in which Web pages are annotated with
semantic information to make their traversal properties explicit. Dante
supports usage of different annotation techniques and as a proof-of-concept
in this article, pages are annotated manually which when transcoded become
rich. We first introduce Dante and then present a user evaluation which
compares how visually disabled users perform certain travel-related tasks on
original and transcoded versions of Web pages. We discuss the evaluation
methodology in detail and present our findings, which provide useful insights
into the transcoding process. Our evaluation shows that, in tests with users,
document objects transcoded with Dante have a tendency to be much easier for
visually disabled users to interact with when traversing Web pages. 


5. Providing Signed Content on the Internet by Synthesized Animation

Written information is often of limited accessibility to deaf people who use
sign language. The eSign project was undertaken as a response to the need for
technologies enabling efficient production and distribution over the Internet
of sign language content. By using an avatar-independent scripting notation
for signing gestures and a client-side web browser plug-in to translate this
notation into motion data for an avatar, we achieve highly efficient delivery
of signing, while avoiding the inflexibility of video or motion capture.
Tests with members of the deaf community have indicated that the method can
provide an acceptable quality of signing.