Manual And Automated Web Accessibility Testing

There are two major approaches to testing the accessibility of web pages. The older one is manual accessibility testing, using a browser, a text editor and our best judgment. The newer method is the use of automated web accessibility testing tools. This article will explore the benefits of both approaches and will suggest how to combine both methods to achieve better results in a shorter amount of time.

Accessibility Testing In A Nutshell

Manual Testing	Automated Testing
Slower	Faster
Completely accurate	Accuracy depends on errors and testing standards
Easier to miss a link	Guaranteed check of all links
Easier to find content which depends on user input	Content can be missed when automated user input is used

Manual Accessibility Testing

Manual testing is one of the safest methods to determine the accessibility of a web page. The accuracy of the results solely depends on the knowledge of the tester. The process involves a thorough understanding of the client side code. This code can be viewed in most web browsers. The tester checks the page structure, and reviews the code where it is necessary. Manual testing allows finding accessibility problems which cannot be found programmatically. For example, a testing tool can determine if an image has descriptive text associated to it, but during manual testing it is possible to determine if the description provides enough information about the image. Manual testing requires a precise systematic overview especially in case of larger sites making sure that all pages and elements are covered.

Automated Accessibility Testing

Automatic testing can provide an initial assessment much faster, and give a good idea of the accessibility of the site on a larger scale. Also, as long as all pages of the site are connected, the tester does not have to worry about missing any pages. While it is a good idea to double check the findings of the automated testing results, when certain problems reoccur several times, once the validity of the problem is established, the tester can file each occurrence much faster. There are, however, certain issues which automated testing cannot detect. This depends on the standards or guidelines we are testing for. For example, when we are testing for a specific syntax, such as valid HTML, color contrast, or the existence of programmatic table headers, automatic testing tools can provide us with 100 percent accurate results. When we are trying to determine if some information is indicated by the use of color only, an automated tool cannot determine it with a good certainty.

Safest Method

Automated testing should always be complemented with manual testing. While we can save a significant amount of time with an automated testing tool, we need to double check the results and rule out other issues. Also, while a testing tool can check for most standards, it is only a human who can tell if the site is easy to use and navigate for a person who is using any assistive technology.

How To Find Accessibility Testing Tools?

You already have one. Any text editor, which will allow you to view and edit HTML will get you started. However, there are some excellent toolbars for web browsers, which could help you determine if a page is accessible. These tools require the knowledge of web editing and accessibility standards.

For Internet Explorer, you can
download the Web Accessibility Toolbar or Learn how to use it.

For Mozilla Firefox, you can
download the Firefox Accessibility Extension or you can
learn how to use it.

The World Wide Web Consortium hosts a number of open source
validators and checkers which can help you create proper HTML, CSS among many other features. These tools can help you put together completely valid code.

Also, on the
World Wide Web Consortium site you can find a list of
web accessibility evaluation tools. These automated testing tools, which will require human judgment to determine the validity of the results. Some of the tools are not free of charge.