Section 5.2: Recommended Accessibility Evaluation Processes, Part 2
Preliminary accessibility review
The W3C identified a process called a "preliminary review". This type of evaluation is not used to determine conformance with a set of accessibility guidelines or standards, but it can identify patterns of accessibility difficulties and does not require knowledge of HTML coding.
The process [ 5 
] uses automated accessibility evaluation tools and manual checking and is broken down into 5 tasks:
- Select a representative page sample
- Examine pages using graphical browsers
- Examine pages using specialized browsers
- Use the automated tools
- Summarize findings
Select a representative page sample
Selecting representative pages means choosing pages that are likely to be places a user enters the site, such as the home page, pages that have design issues of concern (tables, forms) or have a common layout that is used throughout the site.
Examine pages using graphical browsers
Using a graphical browser such as Firefox or Internet Explorer allows you to change the settings in your browser or operating system to check for specific areas that can impact accessibility. The W3C recommended the following steps:
- Turn off images, and check whether appropriate alternative text for the images is available.
- Turn off the sound, and check whether audio content is still available through text equivalents.
- Use browser controls to vary font-size: verify that the font size changes on the screen accordingly; and that the page is still usable at larger font sizes.
- Test with different screen resolution, and/or by resizing the application window to less than maximum, to verify that horizontal scrolling is not required (caution: test with different browsers, or examine code for absolute sizing, to ensure that it is a content problem not a browser problem).
- Change the display color to gray scale (or print out page in gray scale or black and white) and observe whether the color contrast is adequate.
- Without using the mouse, use the keyboard to navigate through the links and form controls on a page (for example, using the "Tab" key), making sure that you can access all links and form controls, and that the links clearly indicate what they lead to.
Examine pages using specialized browsers
Specialized browsers are browsers other than the typical graphical browsers like Internet Explorer or Firefox. Different kinds of browsers such as Home Page Reader, which speaks Web based information aloud, or Lynx, which presents Web pages as text only, can be used to determine if
- the information is equivalent without the page's visual interface
- the information is meaningful in a linear format
The demo version of screen readers can also be used for this step if they are available.
Use automated Web accessibility evaluation tools
The W3C recommends using at least two automated accessibility evaluation tools and includes the manual testing follow-up as part of using these tools.
Summarize obtained results
All of the findings are then summarized. You can describe both positive and negative findings. Make sure you indicate that this was not a full evaluation.
Difference between a preliminary review and conformance evaluation
The difference between a thorough conformance evaluation and a preliminary review is the number of pages evaluated and adding the process of validating the code used. A conformance evaluation typically requires knowledge of and experience with Web accessibility, knowledge of Web development mark-up such as HTML and knowledge of accessibility checking tools. A comprehensive evaluation would also include user testing with individuals with disabilities. [ 5 ]
