S.: Describing images on the web: a survey of current practice and prospects for the future

In a recent large study of Web accessibility (DRC, 2004), blind people complained of two problems with the descriptions of images on Web sites. The first is the lack of descriptions on many images, which should be conveyed via the ALT attribute on the IMG element in HTML. Secondly, those images that do have descriptions often lack useful information. In an endeavour to improve web accessibility through improvement of ALT-text descriptions, this paper presents the findings from the initial stages of a programme to produce a set of guidelines to help web developers produce more useful image descriptions. Firstly we present the results of a survey of current guidelines on how to describe images for blind and dyslexic people and in ALT-text. Then, findings from interviews with blind people on the type of information they would like in descriptions are presented. While those interviewed agree with current guidelines, there are additional aspects that require consideration. Finally, we present results from a survey of 100 homepages of corporate sites from 10 categories. This survey revealed that of the informative images 71 % had descriptions, while only 10 % of the decorative images had descriptions. This result suggests poor adherence to existing guidelines that recommend providing a text equivalent for every non-text element and support the first of the issues raised by the DRC report. Preliminary analysis of the results indicates that the kind of descriptions provided in the 100 pages assessed, were not an adequate text alternative to the image displayed. The results of these studies will form the basis for developing an updated and detailed set of guidelines for image description on the Web