Automatic Accessibility Evaluations


This ADE will provide you with a quick introduction to evaluating computer accessibility. As with the Before and After Considering Accessibility ADE, this ADE continues using the Web for practical examples of technology access.

In this ADE your goal will be to determine to what level a specific website adheres to the recommendations of the Web Content Accessibility Guidelines (WCAG) developed by the World Wide Web Consortium (W3C) as part of their Web Accessibility Initiative (WAI).  Most of the work will be done by an online accessibility evaluation tool.

At the end of this ADE, you will have gained familiarity with an automated accessibility validation tool and how to apply generic recommendations to evaluating an interface.

Note: Several abbreviations and acronyms are used on this page. To help you, they have been marked with  <abbr> or <acronym> tags as needed.   Theoretically, two groups of users can benefit from these HTML elements:


WCAG is part of a series of accessibility guidelines, including the Authoring Tool Accessibility Guidelines (ATAG) and the User Agent Accessibility Guidelines (UAAG). WCAG is primarily intended for:

WCAG 2.0 is the current version of WCAG. It is organized around four design principles each having several guidelines which then have success criteria at level 1, 2, or 3. Success criteria are the testable statements that define how Web content conforms to WCAG 2.0 . Each success criteria has a list of sufficient techniques and common failures. If you implement the sufficient techniques, you meet the success criteria for a particular level. If you have one of the common failures, you do not meet the guidelines for a particular level.

WCAG 2.0 also defines three levels of conformance:

More information is available at the Web Accessibility Initiative homepageWCAG will be discussed in more detail later in the course.

To help you to complete this ADE, you may wish to review information from the Before and After Considering Accessibility ADE.

Using AChecker to Evaluate Web site Accessibility:

AChecker a quality management solution for web sites developed by the Inclusive Design Research Center at OCAD. It checks your web site against the WCAG guidelines. 

For the purpose of this ADE, we will use the web-based version of this tool to test a single live web page. (There is also a version you can download.)

The tool is very simple to use: copy a web address into the textbox and click the button marked "Check It". After a short wait, a resulting report is provided.

The report has five (5) tabs: Known Problems, Likely Problems, Potential Problems, HTML Validation, CSS Validation. 

For the purpose of this ADE, we are only interested in the "Known Problems" tab. If you select the "Known Problems" tab, you will get a report of errors and warnings for all checkpoints assigned a specific WCAG priority level (provided in parenthesis) that may have been violated along with the text of the applicable WCAG guidelines.

Since some of the WCAG guidelines cannot be automated, they will require further (manual) investigation to determine whether their related issues applies to the website as well as whether the website complies with the guideline.

What to Do:

  1. To begin, please listen to the short podcast "Is your Document Accessible?" (local copy used with permission).  

  2. You will use the website accessibility validation tool AChecker to determine to what extent the following websites adhere to the W3C's WCAG 2.0 Web Copntent Accessibility Guidelines:

What to Hand-in:

Submit a report on what you (and the AChecker tool) have found. 

Note:  You are not expected to be experienced web programmers.  If you feel something is too difficult based on your current understanding, you may say it is difficult (where appropriate in your answers to questions 2) because the underlying HTML needs to be first researched/learned.

Be sure to include:

  1. Which Conformance Levels, if any, do each of the webpages currently meet?

  2. What error(s) were identified by the tool at each priority level (in parenthesis) and how easy/hard would it be to correct them?

  3. Compare the results from the AChecker tool against the results of the Cynthia Says tool. How do the results differ?

  4. Feedback
    1. What were your expectations of this ADE?
    2. Did this ADE meet your expectations? Provide a rating between 1 and 7, where 1 means not at all, 4 means somewhat, and 7 means absolutely. Please explain your choice.
    3. Did you feel that the video(s) for this ADE was appropriate? Why or why not? Provide a rating between 1 and 7, where 1 means not at all, 4 means somewhat, and 7 means absolutely. Please explain your choice.
    4. Do you have any suggestions for other possible videos?
    5. Did you feel that the questions above got you to think about the real and serious issues regarding this ADE? Provide a rating between 1 and 7, where 1 means not at all, 4 means somewhat, and 7 means absolutely. Please explain your choice.
    6. If you have any suggestions on how to improve this ADE, please include it here.

What Else You Can Do (optional - not required):

Micorosft also has an accessibility checker that is introduced in a video.