Accessibility Testing – Classification of Tools
Class |
Description |
|
Content Parser-Checker. Examples: WebAIM’s WAVE, AChecker, SortSite |
Tools that process inner elements of the document (tags) and check whether their presence/absence and structure comply with the predefined set of rules.Mostly helpful for testing of requirements:
Well-developed tools are quite useful for quick and cheap catching of obvious bugs. Testers can use them as “smoke testing” tools. Thorough accessibility testing can’t be sufficiently done with tools and no specialized skills. Note. Many commercial tools offer “verify whole site at once”. The important distinction to remember about is that web site is not the same as web application. Web apps requires user to perform input to proceed to the next page, and they generate content on the fly. |
|
Colour Picker-Checker. Examples: Contrast Checker from SSB Bart Group, Colour Contrast Analyser from TP Group, Free browser add-ons. |
Tools that help capturing background and text colour, and perform contrast calculation based on predefined ratios.Mostly helpful for testing of requirements:
Human is fully in control of the process; however, certain dynamic parts (for example, tooltips and mouse-over pop-ups might be hard to grab). Since colour picking is done manually, that can become very long and tedious process. With gradient-based colouring patterns the effort is even bigger. |
|
Colour-Contrast Analyser. Example: Juicy Studio Firefox plugin. |
Tools that analyse the overall colour-contrast of the page based on predefined ratios, and produce compliance report.Mostly helpful for testing of requirements:
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UI Highlighter. Examples: AMP Toolbar from SSB Bart Group, Free browser add-ons. |
Tools that enable locating and highlighting UI elements and controls, and visualize tab order.Mostly helpful for testing of requirements:
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Screen Reader. Examples: JAWS (commercial), NVDA (free). |
A screen reader is a software application that attempts to identify and interpret what is being displayed on the screen. This interpretation is then re-presented to the user with text-to-speech, sound icons, or a Braille output device.That’s the Assistive Technology itself, but it’s also a powerful testing tool that demonstrates the actual usage.For cases in question, Screen Reader is very useful for final decision whether the implementation serves the purpose of enabling the assistive technologies and the implementation is compatible with the Screen Reader. |
|
GUI Automation Tool. Examples: TestComplete, QTP |
GUI automation tools might be employed for regression testing with partial coverage of requirements:
Since GUI automation tools do interact and navigate web applications, it might be very viable to build custom solution to overcome limitations of unified accessibility checkers. Verification of accessibility features in HTML is not different from verification of id, labels, and other elements routinely verified via GUI Automation. |
(This is my work-in-progress classification and may change over time)
