Testing for Accessibility

Triage Your Pages

Accessibility Site Triage is a process developed by the TLT Web Accessibility Team to quickly bring a website to an acceptable, if not perfect, level of compliance with current standards (WCAG 2.0 comformance level AA).

In addition to service sites, triage can be applied to a list of courses (i.e. accessify large enrollement courses first) or a suite of online services maintained by one unit.

Complete Testing Protocol

This protocol will help you address all accessibility errors for a given Web page.

  1. Make sure that all content is available in screen reader or text only mode.
    See Screen Reader Testing
  2. Make sure your page is legible in different color modes and has sufficient contrast between text and background.
    See Color Testing Details
  3. If you use style sheets, then make sure the content is usable with style sheets turned off.
    See Style Sheet Testing Details
  4. Make sure the page zooms well by going to your browser then the View menu and selecting a Text Size option.
    See Zoom Testing Details
  5. You can run the site through accessibility reporting services to see if you have missed any issues.
    See Accessibility Report Details
  6. Solicit feedback from multiple users.

Site Checkers

See limits of accessibility reports to optimize how you process accessibility reports.

Screen Readers

Other Tools

Other Resources

  1. Detailed Testing Protocol
  2. About Accessibility Reporting Tools

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Detailed Testing Protocol

This protocol gives a list of the general types of audiences you are testing for and some methods for testing at each stage.

A. Screen Reader Testing

Use one or more of the following options as needed.

  1. Test sites on a Screen Reader. The following screen readers are available:
    1. JAWS
      Note: There is a demo mode, but the demo license prohibits use of JAWS for Web site testing
      2. Note: JAWS is the screen reader used by the majority of that population
      See also JAWS Keystrokes Reference
  2. NVDA (Windows, open source)
    See also NVDA Keyboard Reference
  3. VoiceOver (Installed on new versions of Mac OS X)
    See also VoiceOver Keyboard Reference (PDF)
  • Use the online WebAIM Wave report to locate ALT tags, HTML headings and other hidden tags. Posts alerts for possible missing elements in red or yellow icons.
  • Illinois iCITA Firefox Accessibility Extension and use the Hide Text Equivalents to show ALT tags. In the Style menu, un-check Author CSS to disable stylesheets
  • Install Fangs Screen Reader Emulator for Firefox. To view a sample page in screen reader mode, go to Tools » Fangs. It does not read text aloud, but displays content from any Web page in screen reader format (no line breaks, headers/tables announced).
  • Computers with screen readers are available at the Penn State Libraries and in some labs designed for users with disabilities. See the Assistive Tech page for details.

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    B. Color Testing

    1. Test color contrast at the Juicy Studio Luminosity Colour Contrast Ratio Analyser or WebAIM Color Contrast Checker
    2. Install and use the Color Contrast Analyzer published by Juicy Studio.
    3. Use a color blindness simulator from the list on the colorblindness page.
    4. Photoshop CS4 includes a colorblindness view in its Proof menu.
    5. View your page or images in grayscale.It's not as effective as a color blindness simulator, but will catch most problems.
    6. In a pinch you can print your page (with HTML backgrounds) on a black and white printer to simulate grayscale.

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    C. Style Sheet Tests

    1. Illinois iCITA Firefox Accessibility Extension. In the Style menu, un-check Author CSS to disable stylesheets

    2. Download the Opera browser which allows you to toogle between Author Mode (with stylesheets) and User Mode (custom or no stylesheet). See the WebAim Opera article for more details.

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    D. Zoom Testing

    Open a browser and zoom to at least 200%. This will simulate what a low vision user or mobile user on a small screen will experience.
    Note: In older browsers, the wrong CSS specification would disable text enlarging, but this has been fixed in most older browsers.

    • To zoom in Firefox, go to View then Zoom In about 4 times.

    E. Accessibility Reports

    See the section below for detailed information about accessing and evaluating accessibility reports.

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    Accessibility Reports

    A variety of organizations and companies have developed tools to "scan" Web pages and see if they are accessible or not. Although these tools can catch some errors like missing ALT or TH tags, they cannot catch all errors. You must still use the manual checks above to determine that all accessibility requirements have been met.

    Common Reporting Tools

    Some common reports include:

    Lists of Manual Checks

    For errors that cannot be caught automatically, a list of manual checks, is generated. Therefore a completly compliant site could still generate a list of items to check depending on the reporting tool - this is perfectly normal.

    Limits of Accessibility Reports

    Below are some advantages and limits of accessibility reporting tools.
    (Chart provided by the University Libraries)

    HTML Element Reports CAN Reports CANNOT
    Images Check for Missing ALT tags Verify that ALT tags are accurate
    Color Suggest manual color check Simulate Color Blindnesss modes
    Data Tables Identify most missing TH tags Check that tables are coherent when read left-to-right, top-to bottom
    Flash Objects Suggest manual check Determine accessibility of Flash forms or interactive modules
    Style Sheets Suggest manual check without CSS sheets Check stylesheets for accessibility
    Links Identify large blocks of links Identify links which are vaguely worded or too close together
    Forms Identify missing LEGEND, LABEL and ID tags Fix them for you automatically or ensure that they are accurate
    Javascript Suggest manual NOSCRIPT check Automatically insert a NOSCRIPT alternative
    HTML Code Validation Do Nothing HTML and XHTML validation is completely different tool or report

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