What is Progressive Enhancement?
Progressive enhancement, or PE, is a strategy for web design that emphasizes accessibility, semantic HTML markup, and external stylesheet and scripting technologies. Progressive enhancement uses web technologies in a layered fashion that allows everyone to access the basic content and functionality of a web page, using any browser or Internet connection, while also providing an enhanced version of the page to those with more advanced browser software or better bandwidth.
According to many web experts offering some of the best web design services, Progressive Enhancement consists of the following core principles: (1) basic content should be accessible to all web browsers, (2) basic functionality should be accessible to all web browsers, (3) sparse, semantic markup contains all content, (4) enhanced layout is provided by externally linked CSS, enhanced behavior is provided by unobtrusive, externally linked JavaScript, and (5) end-user web browser preferences are respected.
Web pages created according to the principles of PE are by their nature more accessible, because the strategy demands that basic content always be available, not obstructed by commonly unsupported or easily disabled scripting.
Additionally, According to many web experts offering some of the best Philippine web design, the sparse markup principle makes it easier for tools that read content aloud to find that content. It is unclear as to how well PE sites work with older tools designed to deal with table layouts, "tag soup," and the like.
Benefits in SEO or Search Engine Optimization
Improved results with respect to search engine optimization are another side effect of a PE-based Web design strategy. Because the basic content is always accessible to search engine spiders, pages built with PE methods avoid problems that may hinder search engine indexing.
Some skeptics, such as Garret Dimon, have expressed their concern that PE is not workable in situations that rely heavily on JavaScript to achieve certain user interface presentations or behaviors.
Others have countered with the point that informational pages should be coded using PE in order to be indexed by spiders, and that even Flash-heavy pages should be coded using PE.
In a related area, many have expressed their doubts concerning the principle of the separation of content and presentation in absolute terms, pushing instead for a realistic recognition that the two are inextricably linked.
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