Wednesday, January 25, 2012

Accessibility testing

Accessibility testing  for web sites is a service that can provide much more than the standard point-by-point testing techniques of most automated services.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.

It provides a more detailed analysis of the content and layout of the page elements, yielding optimization procedures for a variety of circumstances that can be used during the development process of a site, site remodeling, or ongoing evaluation and monitoring of an existing site.

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. 

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.
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.

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.

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