What is Web Accessibility?

Accessibility
Accessibility is a general term used to describe how easy it is for people to get to, use, and understand things. (Wikipedia)

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It is a common mistake to believe that accessibility refers exclusively to the relationship between people with disabilities and their environment. That is, that making a building, website, or other device "accessible" is merely the process of ensuring that a person with a disability will be able to use it. This is not precisely wrong; it is merely incomplete.

Making a website accessible goes well beyond providing access to the most obvious market, which is users with visual disabilities. What I'm going to describe in this article are general descriptions of the areas where accessibility needs must be taken into consideration and a brief discussion of some of the techniques used to accomplish those needs.

Technology Problems

Yes, one of the biggest barriers to the use of a website can be technology itself. If the entire world was using a single browser on one computer, then technology would cease to be an issue. However, this is very far from the case!

Browser Choice

Although Internet Explorer is by far the most popular browser available, it is also the least compliant with web standards. Other browsers together constitute approximately 15-20% of web traffic. Obviously, you don't want to alienate up to 20% of your potential visitors by providing an inferior experience! A critical element to start your web accessibility process is cross-browser testing. I routinely test in Internet Explorer 6 and 7, Firefox 1.5 and 2.0, and Opera 9 for Windows and for Safari, Firefox, and IE 5.2 for Mac.

Connection Speed

Patience is a virtue. However, when the internet boasts millions of website - why should a visitor take the time to wait 5 minutes for yours? The average visitor will usually wait no more than 8 seconds for an unknown website to load. As of the middle of 2006, only about 50% of users are on broadband connections. Keeping the size of your website to a manageable level, using a minimal degree of multimedia and other high-bandwidth imagery is a key goal to accessibility.

JavaScript

Many browsers default to surf the web without JavaScript, and some users opt to turn JavaScript off for security reasons. Either way, excessive use of scripting can greatly degrade the ability of your site to function for some users. Although it's by no means necesary to completely avoid JavaScript, accessible web design should always include alternate methods of accomplishing anything which would normally require JavaScript. The most common area for JavaScript to come into play is site navigation - and the last thing you want is for your visitors to be unable to navigate your site.

PDAs and Mobile Devices

The mobile internet is a rapidly growing segment of internet use. If your website is not accessible to mobile devices, you may be missing out on a large segment of potential traffic - and mobile browsers have a whole host of complications. Mobile internet browsers have a hugely variable degree of support for images, style sheets, and scripting. There are guidelines for best practice in mobile design which it's critical to follow for a successful mobile website.

Users with Disabilities

The range of disabilities which can be impacted by your web site design is tremendous. The most common category cited is blindness or low-vision, but in fact there's a huge range of potential issues in addition to those.

Blind Users

Blind users require the use of a screen reader to browse the internet. Screen readers function by reading the content of the web page to the user. Rather than merely reading the visual content, screen readers actually process the HTML code of the page. Because of this, you can provide a wide variety of helpful accessible codes for screen readers within the page. These codes can help blind users to:

However, some common web design techniques, such as using tables for layout, can cause screen readers to become very confused about the correct order in which to read the page. This design can prove confusing and unusable to a blind user.

Partial or Low Vision

Particularly with the growing population of individuals over 50, issues with fading eyesight are becoming more and more important. Providing a high enough contrast and large enough text for the text to be readable is critical to providing a satisfying web experience for any user with vision problems. The text on a website should be resizable, and frequently it's a well-considered move to provide alternate views of the site with high contrast or very large text.

Color Blindness

Careless choice of colors can render your website entirely worthless to a color blind individual. Testing for inappropriate color choice and making certain that color is never the sole distinguishing factor between two items is necessary to provide an accessible site.

Keyboard or Alternate Device Navigation

Users with mobility problems including cerebral palsy, Parkinson's, quadriplegia or any of a wide variety of other physical disabilities may not be able to use a mouse. Websites should never require a mouse to perform any action. All links on a website should become highlighted clearly not only when the mouse hovers over them, but also if they've been selected using the tab key or other pointing device.

Deaf Users

It is a common misperception that the deaf do not suffer problems when visiting web sites. They can see - so they should be able to read your text without any difficulty! In many cases this is true. However, some individuals who were born deaf can have difficult processing written text. And all deaf users will have a great deal of trouble with any audio or video with audio files! For any audio information, a transcription should always be provided.

Users with Learning Disabilities

Dyslexic users or users with autism may have difficulties processing certain types of information. Users with dyslexica may find text confusing, and be aided by clear graphical symbols associated with appropriate actions. Autistic individuals may have difficulties with idiomatic speech, metaphor, or other non-literal forms of speech.

Summary of Accessible Web Design

This article has only provided a cursory explanation of the issues surrounding a fully accessible web design. Any one section of this explanation could spawn an entire article of its own - and most of them have spawned several. For more reading:

Also by Joe Dolson:

Other valuable references:

These are just a very few of the many great articles available online about web accessibility - Contact me if you want more suggestions of good resources, or search yourself!

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