User interface guidelines

As MediaWiki's user interface continues to evolve, it is critical to adhere to a common standard for style, usability and accessibility.

Style
Information about use of color, icons and other kinds of visual coding needs to be outline here.

Usability
While it's possible, and common, that despite conformance to guidelines user interfaces can still have usability problems, understanding and following these guidelines will help eliminate the vast majority of common usability failures.

Scalability
User interfaces should be scalable, supporting a variety of character height and text length scenarios.

Although many modern browsers default to scaling web-pages using a zoom technique, most still support scaling only text. Using "em" measurements in style sheets can ensure that user interface elements can scale together with text size changes where appropriate. User interfaces are localized into about 250 languages, many of which exhibit extremely different text lengths for any given text written in English. Avoid using static widths combined with static heights, even if they are being set in "em" units; allow the browser's text-flow to determine either the width or height of a text container. Testing with a variety of extreme cases such as German, which is typically more lengthy and Chinese which is typically more brief, will help identify problem areas.
 * Allow text to scale up to 200% or down to 50% of it's original size.
 * Allow for text to flow correctly in any language.

Accessibility
The W3C has a comprehensive set of Web Content Accessibility Guidelines (WCAG). These guidelines, which help users with a variety of impairments participate on the internet, would ideally be conformed to whenever possible.


 * 1) Provide equivalent alternatives to auditory and visual content.
 * 2) Don't rely on color alone.
 * 3) Use markup and style sheets and do so properly.
 * 4) Clarify natural language usage
 * 5) Create tables that transform gracefully.
 * 6) Ensure that pages featuring new technologies transform gracefully.
 * 7) Ensure user control of time-sensitive content changes.
 * 8) Ensure direct accessibility of embedded user interfaces.
 * 9) Design for device-independence.
 * 10) Use interim solutions.
 * 11) Use W3C technologies and guidelines.
 * 12) Provide context and orientation information.
 * 13) Provide clear navigation mechanisms.
 * 14) Ensure that documents are clear and simple.

The W3C has also begun a Web Accessbility Initiative (WIA), which is a continuation of the guidelines set forth in the WCAG. Accessibility for Rich Internet Applications (ARIA) describes a set of best practices and defines a set of embeddable markup "hints" which can be added to web applications to facilitate their use by interactive screen reading software. These practices and guidelines would ideally be utilized and conformed to whenever possible.

External Resources

 * Web Content Accessibility Guidelines
 * Web Accessbility Initiative
 * Accessibility for Rich Internet Applications
 * User Focus - 247 Usability Guidelines