Accessibility Testing

By Anand Ramdeo on May 5, 2011 Comments

Accessibility testing is the technique of making sure that your product is accessibility compliant. There could be many reasons why your product needs to be accessibility compliant as stated above.

Typical accessibility problems can be classified into following four groups, each of them with different access difficulties and issues:

Visual impairments

Such as blindness, low or restricted vision, or color blindness. User with visual impairments uses assistive technology software that reads content loud. User with weak vision can also make text larger with browser setting or magnificent setting of operating system.

Motor skills

Such as the inability to use a keyboard or mouse, or to make fine movements.

Hearing impairments

Such as reduced or total loss of hearing

Cognitive abilities

Such as reading difficulties, dyslexia or memory loss.

Development team can make sure that their product is partially accessibility compliant by code inspection and Unit testing. Test team needs to certify that product is accessibility compliant during the functional testing phase. In most cases, accessibility checklist is used to certify the accessibility compliance. This checklist can have information on what should be tested, how it should be tested and status of product for different access related problems. Template of this checklist is available here.

For accessibility testing to succeed, test team should plan a separate cycle for accessibility testing. Management should make sure that test team have information on what to test and all the tools that they need to test accessibility are available to them.

Typical test cases for accessibility might look similar to the following examples -

  • Make sure that all functions are available via keyboard only (do not use mouse)
  • Make sure that information is visible when display setting is changed to High Contrast modes.
  • Make sure that screen reading tools can read all the text available and every picture/Image have corresponding alternate text associated with it.
  • Make sure that product defined keyboard actions do not affect accessibility keyboard shortcuts.
  • And many more..

There are many tools in the market to assist you in your accessibility testing. Any single tool cannot certify that your product is accessibility compliant. You will always need more than one tool to check accessibility compliance of your product. Broadly, tools related to accessibility can be divided into two categories. Inspectors or web checkers

This category of tool allows developer or tester to know exactly what information is being provided to an assistive technology. For example, tools like Inspect Object can be used to get information on what all information is given to the assistive technology. Assistive Technologies (AT)

This category of tools is what a person with disability will use. To make sure that product is accessibility compliant, tools like screen readers, screen magnifiers etc. are used. Testing with an assistive technology has to be performed manually to understand how the AT will interact with the product and documentation. More information on the tools is present in tool section of this website for you to explore.

Some tips that can be used for Accessibility testing .

  • When using a screen reader, be sure to include tests for everything the user would be doing, such as install and un-install of the product.
  • If a function cannot be performed using an Assistive Technology, then it may be considered accessible if it has a command line interface to perform that function.

Most of the time on windows platform, accessibility is built in your product using Microsoft Active Accessibility (MSAA). You can get more information about MSAA on this page.

What is MSAA?

MSAA is the abbreviation of Microsoft Active Accessibility. MSAA is a set of dynamic link libraries (DLLs) that provide COM interface and APIs. It is incorporated into the Microsoft Windows operating system and provide methods for exposing information about UI elements.

MSAA is used by assistive technologies like screen readers. These tools get information from the MSAA and gives to the user. MSAA gives information in the form of objects. Every UI element is treated as UI object and information like Name, Value, Role, State, Keyboard Shortcut, etc. is given to the tools for assistive technology. MSAA also supports events to capture state changes in the UI objects, for example object focus changes.

Today most screen readers expect that application have implemented MSAA. Implementing MSAA is probably one of the easiest way to ensure that assistive technologies will work with your product.

MSAA Software Development Kit contains following tools:

Inspect Objects

Displays object information for user interface objects

Event Watcher

Displays events fired by application when navigating the user interface

Accessible Explorer

Displays object properties and relationship hierarchy

Development team can use these tools to find accessibility related defects in the development phase. Test team can validate that product is accessibility compliant using these tools and some other

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