Beyond web content accessibility guidelines: Design of enhanced text user interfaces for blind internet users

Websites do not become usable just because their content is accessible. For people who are blind, the application of the W3C`s Web Content Accessibility Guidelines (WCAG) often might not even make a significant difference in terms of efficiency, errors or satisfaction in website usage. This paper documents the development of nine guidelines to construct an enhanced text user interface (ETI) as an alternative to the graphical user interface (GUI). An experimental design with 39 blind participants executing a search and a navigation task on a website showed that with the ETI, blind users executed the search task significantly faster, committing fewer mistakes, rating it significantly better on subjective scales as well as when compared to the GUIs from other websites they had visited. However, performance did not improve with the ETI on the navigation task, the main reason presumed to be labeling problems. We conclude that the ETI is an improvement over the GUI, but that it cannot help in overcoming one major weakness of most websites: If users do not understand navigation labels, even the best user interface cannot help them navigate. (c) 2007 Elsevier Ltd. All rights reserved.