Testing Scripts for Accessibility
It has been mentioned in other modules that the best way to test your site is to have individuals with
disabilities examine it for potential barriers. Because they work with the technology on a day-to-day
basis, they will be able to evaluate your site from a different perspective, and point out things of which the developer
may not have been aware.
Finding someone like this can be difficult; fortunately, there are other approaches to testing your site.
Because there are many individuals who have browsers
that are not able to interpret scripting, one of the best ways to test
your site is to turn off scripting in your browser and determine if the
site is still usable, especially the navigation. This will also give you
a feel for how people interact using the keyboard.
To turn off scripting in Internet Explorer:
- Under the 'Tools' menu, select 'Internet Options'.
- Select the 'Security' tab.
- Select the 'Custom Level' button.
- Search for the the 'Scripting' section. (see Image
2)
To turn off scripting in Netscape:
- Under the 'Edit' menu, select 'Preferences'.
- Select 'Advanced'.
- Search for the scripting section. (see Image
3)
To turn off scripting in Mozilla Firefox:
- Under the 'Tools' menu, select 'Options'.
- Select the 'Content' tab within this menu.
- Deselect the 'Enable Java' and 'Enable Javascript' checkboxes.(see Image
N4)
Lynx was one of the first web browsers, and is often
used as a way to check a website overall for accessibility. It is free
to download Lynx
.
Some benefits of testing with Lynx are that it is a text-only browser
that does not support scripting and the method of interaction is keyboard
navigation. Using Lynx will provide insight into the tabbing order of
your site, expose navigational deficiencies, missing alternative text,
and can help uncover other basic accessibility barriers.
Image
4 offers
an example of how Lynx would
look; the "Google" website is being viewed.
A JavaScript tester
named Snork
has been developed. Snork will work on IE5 with Windows 95', or later versions of either.
The Snork program has the ability to examine scripts and check for some of
the more obvious mistakes as well as generate reports
that both identify and present potential solutions to accessibility problems. A
sample report from Snork
is available online for your review.
General Scripting Guidelines
The content that
has been presented on this page is not complete. It would be difficult
to cover all programming scenarios; scripting can create an infinite amount
of situations, only limited by the programmers imagination. Below is a
list of general scripting guidelines that can be applied in most situations.
- The NOSCRIPT tag allows the developer to supply alternative text for
browsers that do not support script. However, this is essentially the
same as maintaining two sites, so should be used with caution.
- Do not rely solely on the scripting language for important features
like navigation.
- Pop-up windows can be disorienting.
- If the script contains blinking or moving text, provide a way to pause
it.
- Do not call scripts from within a link. This can hinder those who
use keyboard-only navigation, or who use browsers that do not support
scripts.
- Avoid expanding menus. They are unusable.
- Layout forms so they are read correctly by a screen reader.
- Do not use invisible text such as black text on a black background.
This was an old trick to improve ratings for search engines. Chances
are, this data will be read by the screen reader, and will not raise
your rank on the search engine.
The next page will discuss applets and Java.