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Navigation
Objective:
Develop an understanding of how navigation can impede accessibility and how to design accessible navigation.
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Develop an understanding of how navigation can impede accessibility and how to design accessible navigation.
Navigation is a serious problem for blind or visually impaired people because of how screen readers and talking browsers speak a Web page. This is particularly true of a Web page that uses layout tables for navigation.Screen readers and talking browsers use a technique called linearizing to convert a Web page to a sequence of words and lines. The assistive technology first converts images to their alternative text. Then it spreads out (linearizes) the tables a cell at a time, working from left to right across each row. If a cell of a table contains a table, that table must be linearized before moving on to the next cell.
Example of how some text readers might read a non-linearized navigation table
Creating Accessible Navigation
A consistent style of presentation on each page allows users to locate navigation mechanisms more easily but also to skip navigation mechanisms more easily to find important content. This helps people with learning and reading disabilities but also makes navigation easier for all users. Predictability will increase the likelihood that people will find information at your site, or avoid it when they so desire.
If you choose to use a table rather than navigation bar for your website it is important to make sure the table is ordered properly so that a screen reader presents it in an order that make sense.
The problem lies in the table's HTML code structure. When the screen reader linearizes the table, it reads all the text in the first cell of row one, the second cell, the third, and so on until it runs out of cells. Then, it reads the first cell of row two, the second, etc. This is a perfect sequence for tabular data - especially if you've optimized the table for accessibility - but it doesn't work as well for layout tables.That's because the structure of layout tables is usually much more complex - with cells used for banners, navigation, content, images, etc.
When designing Navigation Tables it is important to make sure that they read in the correct order. To check your navigation try Tablin
Skip Navigation
A Skip navigation link provides a method for individuals using screen readers and other assistive technology to skip navigation and go directly to the content.at the top of the page, you'd put:
<a href="#navigation">Skip to navigation links</a>
If you don't like the look of the text links, use single-pixel gifs to add the links. They'll be invisible to most visitors, but easily accessible to visitors using screen readers.Use can also use a skip navigation text link that is the same color as the background in order to blend in to the graphic or background.
Tab Key can be used for navigation for individuals who cannot use the mouse, the tab key allows them to move through the navigation links.