Computer accessibility

     From Wikipedia, the free encyclopedia.

In human-computer interaction, computer accessibility refers to the usability of a computer system by people with disabilities. It is largely a software feature.

There are several types of disabilities that impact computer use:

• Complete or partial blindness, in particular colorblindness.
• Hearing impairment.
• Motor disability such as carpal tunnel syndrome resulting in mobility impairment.
• Difficulties caused due to old age.

The biggest challenge in computer accessibility is to make software usable for people with visual impairment. For people with poor vision, it is helpful to use large fonts, high-contrast icons etc. supplemented with auditory feedback and screen magnifying software. In the case of blindness, text to speech (screen readers) and speech recognition software is essential.

About 10% of people suffer from some form of colorblindness. In a well-designed user interface, color should not be the only way of distinguishing between different pieces of information.

Some people may not be able to use one of the input devices, the mouse or the keyboard. Therefore it is important for software functions to be accessible using both of them. Keyboard shortcuts and mouse gestures are ways to achieve this. More specialized solutions like on-screen keyboards and alternate input devices like joysticks and trackballs are also available.

The astrophysicist Stephen Hawking is a famous example of a person suffering from motor disability. He uses special software that allows him to control his computer using the movement of only two fingers.

On the World Wide Web, the W3C has produced specific guidelines for accessibility. The Cascading Style Sheets system has been devised with this in mind, since it gives the reader full control over the appearance of the page.

As an example, most web browsers have an option to ignore the font size specified in a webpage, so that the user can circumvent a small font forced upon him or her by a webpage author. However, sometimes a webpage author fails to take into account that users may want to apply such an option and designs a webpage such that applying this option gives poor results, such as too small a distance between lines, disabled scrolling even though texts do not fit in assigned spaces, overlapping texts, etc.

External links

• Web Accessibility Initiative
• Microsoft Accessibility
• Web Design Reference - A huge mega-reference (over 3,000 links) of information and articles dedicated web design and development. The site advocates accessibility, web standards, usability and many related topics. It features a listserv and RSS feed for site updates.
• The GNOME Accessibility Project
• The KDE Accessibility Project
• Accessibility in the Opera web browser
• Mozilla Accessibility Project
• Accessify Forum
• AccessibleNet.org
• Accessibility article from Lux