Accessibility Factors

Accessibility is a huge issue with web design, especially CSS positions. The way the CSS page lays out the final web site can mess around with a couple of things making it hard for certain people to use a site. There are many factors that come into play with the layout of a page and if it is accessible or not. Things such as the browser that is being used, screen readers for the blind and monitor size. If web designers just followed a few simple rules, or methods, then accessibility wouldn't be a problem.

Relative positioning is positioned by the normal rules then is changed by the offset properties. The content in the div tag can overlap another. This is all based upon the offset properties. Now where accessibility comes into play is how different brewers handle the information.

"Browsers may differ in how they handle the display of relatively positioned elements when they overlap other content. Unfortunately, the standards specification appears unclear in how this should be dealt with.

Some, like Internet Explorer 5.5 and Netscape 6.0, will display the positioned element in front of all its siblings. Others, like Opera 5.0, use the default stacking order and will display it in front siblings that proceed it in source order but behind siblings that follow.

Stacking order is detailed in the discussion on absolute positioning. But note that you can use the z-index style property to explicitly set the stacking order for relatively positioned elements (brainjar.com)."

Descendant positioning is a relative element but decides depending on if the element is block or inline. The rules on accessibility have changed before new elements had to be created in new blocks, now boxes follow non-positioned elements rules. Some browsers correct this problem; others do not.

Screen readers talk in the order of the code, not in the order of the screen. Once a screen reader starts to read the CSS markup it goes down in order. So if there are more important things on the page, you might want to put them closer to the top. This is where different layouts come in. An absolute layout would be better to use because it places the content is the same spot is a left to right order making it easier for the screen reader. Relative might confuse the screen reader because it moves it around.

CSS layout is important for accessibility. It can also help people with poor sight. When writing the CSS separate styles can be set so it makes it easier for the font size to be increased in the browser. Also, if the user has a smaller screen the positioning and layout and be automatically fit to the screen resolution. All of these factors and more make web accessibility what it is when using CSS.

Work Citied

CSS Positioning. 2007. Brain Jar. February 2007. http://www.brainjar.com/css/positioning/default3.asp