Progressive Enhancement
People have the right to obtain information and services from web sites regardless of the technologies they use. The key to effective implementation of universal accessibility lies in designing sites to serve the widest possible audience and the broadest possible range of hardware and software platforms, from adaptive technologies to emerging technologies.
In the past, the graceful degradation approach was used to ensure the widest possible audience was being served. The graceful degradation approach involves designing a Web site for one or more target configurations, then including functional but degraded support for other configurations. The graceful degradation approach works well when designing a basic template, but it can be problematic since it tends to limit the introduction of emerging technologies and enhanced interface options to ensure compatibility with adaptive technologies and other configurations.
As a result of these limitations, there has been a shift in recent years away from the graceful degradation approach towards the progressive enhancement approach for embedded multimedia and other Web page enhancements. The progressive enhancement approach involves designing Web content for the least capable configurations first, and then introducing a series of enhancements based on the capability of each client’s configuration. This approach is an improvement over graceful degradation because it encourages the introduction of emerging technologies and enhanced interface options without compromising the support for less capable configurations.
