Usability and transparency in the design of a tool for automatic support for web accessibility validation

The importance of guaranteeing accessible Web applications is becoming widely recognised, and supported by national and international legislation. This implies an increasing need for large scale validations, which can be achieved only through automatic support. Thus, there is a need for a new generation of accessibility validation tools able to check against the continuously evolving guidelines and report any issues revealed, considering that their results will be used by many people with varied backgrounds and goals. Such tools should be able to support monitoring of Web sites' accessibility, provide user-friendly information suitable for various purposes, and be transparent in terms of what they are actually able to evaluate in order to elicit the right expectations from their users. They should also consider how the technologies for implementing Web sites have evolved in recent years. In this paper, we provide a description of the requirements and design dimensions that characterise such tools in order to address emerging needs, providing indications on whether and how several existing validation tools support them, and present how we have addressed and implemented them in a specific tool. We also report on a first usability test of such tool, which has provided encouraging feedback.