Introduction to Web Accessibility and Usability Testing

• In Accessibility Testing we follow the Web Content Accessibility Guidelines (WCAG v1.0) (You should read (EN) something about or maybe in Spanish) from the Web Accessibility Initiative (WAI). There are two Spanish rules: UNE 139802:2003 y UNE 139803:2004 that focus n the same.

The WCAG v1.0 consist of three priority levels, each of them has some points that a web application has to carry out.

A web application carries out Level A in Accessibility if it carries out with the 16 points of the first priority level.
A web application carries out Level AA in Accessibility if it carries out with the points before and the 30 points of the second priority level too.
A web application carries out Level AAA in Accessibility if it carries out with the points before and the 19 points of the third priority level too.

We always try to carry out at least the Level AA in the Accessibility of web applications.

It's important to add, that there's a new law called Ley 56/2007, de 28 de diciembre, de Medidas para el Impulso de la Sociedad de la Informaci�n which sais:

�Since 31st of Decembre 2008, the web pages from Spanish Goberment will have to carry out at least the medium level of the accessibility criteria general recognised.�

This is real important, because there is a law now that obliges to carry out Level AA.

• Accesibility tests consist of:
  1. First, choice a couple of web pages from the application that are characteristic. Accessibility Tests will focus on these pages.
  2. Then we use TAW (Test de Accessibilidad Web), a very useful application, that tests automatically every point of the WCAG v1.0 and returns which points does the application carry out and which points it doesn't.
  3. TAW can't test automatically some points of the WCAG v1.0 and therefore you need to use some other applications:
     • Alternative Web Browsers to verify that the application works with them too: Internet Explorer, Firefox, Opera, �
     • Web Accessibility ToolBar from Accessible Information Solutions (AIS) for IE Browser. With these tool, css, javascript, images can be deactivated in the browser easily.
     • CA2BD: Tool to test colour and brightness contrast of the different elements in a web page.
     • Firefox Extensions:
       • Web Developer v1.1.5: Very useful extension to deativate css, javascript, images, �
       • Fangs: A screen reader emulator. Extension that shows the text from the web page that would play a screen reader.
       • Colour Contrast Analyser: Extension that tests the colour and brightness contrast of the different elements in a web page.
       • Html Validator: Extension that shows the HTML errors of a web page.

Web Usability

Usability is relative new and Usability Testing are just starting. It measures the user's effectiveness, efficiency and satisfaction using something, in this case a web application. This concept is a little bit abstract and it's based on logic, deduction and experience of: why is better for the user to have radio buttons than a list of options, or having the Accept option on the left of Cancel and not in another way, �

The most interesting guidelines nowadays are the Usability Guidelines (106 Mb) defined by the American Government.