Could you provide examples of best/worst practices on how to make websites accessible ?

The W3C offer several guidelines and techniques on how to make accessible web content. For the Norwegian context you will find helful materials at

What can I do to improve the accessibility of my web site?

You can start out by checking one page on your web site using the Checker (e.g. the main page). Try to improve the page by removing the barriers detected. Some issues might require changes in the work flow of content production e.g. training the editors to produce more accessible content. While other issues have to be addressed by the web site developers, e.g. changing from layout tables to a flexible CSS layout, or by the CMS vendor, such as changes in templates you may not have access to. You can also get more feedback from an accessibility consultant. And most importantly, listen to the users of your site and provide a way for them to report problems they encounter. In general, the higher score you get with the Tingtun Checker the more accessible your web page is. For more information see the WAI compilation on "Improving the Accessibility of Your Web Site ".

What do I need to consider to write a good alt-text?

The generic rule for the alt attribute is to use text that fulfills the same function as the image. See also

What is a barrier and why should I care?

A barrier is an obstacle which is challenging or impossible to overcome for some users, such as having the only entrance to a building through staircases, preventing a person in a wheelchair to enter the building. Poorly designed web sites may also contain barriers. As an example, some web sites are designed in such a way that users are required to use a mouse to navigate within the web site. People who have challenges with using a mouse, like persons with motor impairments, or mobile phone users, will experience this as a barrier and may not be able to use the web site at all. An accessible web site is barrier free and works for all users, including users with special needs, such as users who are visually impaired, dyslexic, colour blind, are using a mobile phone to navigate etc. If your web site is barrier free, more people can use your web site. For more information see the " WAI Resources on Introducing Web Accessibility".

What is WCAG?

The Web Content Accessibility Guidelines (WCAG) are guidelines intended to explain how to create accessible web content. WCAG is a web standard from the Web Accessibility Initiative (WAI), a part of the World Wide Web Consortium (W3C). WCAG 2.0 were published in December 2008. The EIII Checker is based on WCAG 2.0. For more information read the WCAG overview.

Why is it that reliable and well linked sites like Google also fail several tests?

The accessibility of websites is not correlated with how known the website is, but with how it is implemented.