Usability, Accessibility & Compatibility
Information architecture, content development, web usability and accessibility design and site compatibility all effect how users find the information they want and complete web-based tasks. Good design makes these tasks easier and more efficient for a range of different users.
Usability
Web usability refers to:
- how easily the user finds the information they want
- how accessible the site is to adaptive technologies like screen readers and screen magnifiers
- how compatible the site is with the user's hardware and software
Usability issues are central to every aspect of best practice web development, from site architecture to visual and interactivity design. Usability should inform almost every decision made about the site. Site testing is an important part of monitoring web site usability.
Accessibility
Good design makes web sites more accessible, particularly to users with disabilities who access sites with adaptive technologies like screen readers and screen magnifiers. Implement usability principles right from the start of web development - it's much harder to 'retrofit' a web site for accessibility once it has been completed.
Designers should be aware of current accessibility guidelines before they begin to build the site. These guidelines are improving all the time as we aim to make web-based information more inclusive and able to support task performance for users with disabilities.
The World Wide Web Consortium (W3C) has documented generally accepted standards and guidelines for producing accessible web content. These can be found under W3C's Web Accessibility Initiative resources. The most essential document is the Checklist for Web Content Accessibility Guidelines 1.0. All new web sites should adhere, at the very least, to Priority 1 checkpoints.
Basic accessibility guidelines
- Always use the 'alt' tags on images
- Provide alternative text links for all image links
- Use appropriate colour contrasts
- Use appropriate typography, ie. font styles and sizes
- Provide alternative content to audio content
- Use appropriate design parameters for screen readers, eg. for table layout
- Use the clearest and simplest language appropriate for the site's content
- Test the site on screen readers and screen magnifiers
Compatibility
Good design ensures that there is maximum site compatibility, stability and accessibility in a range of different platforms and browsers. Designers must be acutely aware of the differences between platforms, operating systems and server technologies so that they can account for and accommodate these differences during web development.
Identify and resolve problems early by testing web site compatibility regularly during the web development process. Site testing should include checking the behaviour of the site in a range of currently used browser versions, including common browsers like Netscape Navigator and Internet Explorer and some of the less common browsers like iCab and Opera.