Skills for Access

Description

Scalable Vector Graphics (SVG) is an open technology for the creation of media rich animated content accessible across different browsing environments. A language based on XML, SVG has been developed by the World Wide Web Consortium (W3C) so is freely available for anyone to use regardless of browsing platform. In theory, animated graphical and audio presentations can be created by writing an SVG file using a simple text-editor; in practice an SVG authoring tool will allow easier creation of complex SVG resources.

To access SVG content requires a user to have an SVG player or browser that natively supports SVG. At the time of writing (March 2005), native browser support for SVG is limited to some open source browsers, and even then implementation is not complete - although this situation is expected to change!

Accessibility Issues

SVG has many potential advantages from an accessible multimedia and e-learning perspective. Animated content can be used to illustrate and enhance textual content, thus making information and concepts easier to understand for people who find it difficult to process textual information. Since it is based on XML, the structure of the language supports direct provision of appropriate text alternatives to graphical content. As a vector-based graphics format, like Flash, it is possible to resize SVG content with no adverse effect on visual quality, making enlarging of content possible for people with low vision.

However, SVG is very much a technology still in development, and some accessibility barriers have been identified which currently limits the potential of SVG as a means of delivering accessible multimedia. For example, there are problems with keyboard accessibility to interactive SVG content, which remain to be fully addressed.

As a technology for producing animated visual content, SVG authors must also be conscious of the accessibility barriers that may be introduced through using animated content, and how their impact may be reduced or avoided. For example, access barriers can result from inappropriate use of flickering or flashing content, which may be distracting or even induce seizures, or reliance on the use of graphics or colours. In some cases, the SVG content can be designed to reduce the impact of these barriers, in other cases, presentation of information in an additional alternative format will be necessary.

In general, the comparative lack of mainstream use of SVG at the time of writing means that examples of accessible SVG for e-learning are extremely hard to come by.