Charts & Graphs, Web Accessibility, The University of Arizona

Requirements:

The content and meaning of a chart or graph should to be described in text to make it accessible to all users. However, not all charts or graphs can be easily summarized.

Contact Information:
If a chart or graph can not be easily summerized, provide contact information so that a user can contact you for more information.
Alt Tags:
Charts and Graphs that are created using a graphic file, must have provide an Alt tag that describes the content of the chart.
```
	<img src="enrollment.gif" height="100" width="150" 
	alt="Student enrollment has increased 10 percent in the last year.">
```

D-link [optional]:

One way to describe a chart or graph in more detail is to use a description link, normally called a D-link. Rather than spell out "description link", the convention is to use a single letter of D near the chart, which (when selected) takes the user to another document describing the chart/graph. It could go elsewhere on the same document with the textual explanation, but most of the examples show a link to a separate document.


        <img src="enrollment.gif" height="100" width="150" 
	alt="1999 undergraduate enrollment"><a href="99enrollment.html">d</a>

In the example above, a sighted person would see the D next to the chart, and a screen reader would speak the letter D.

You can also make the D invisible, still placed next to the image, but having an alt text of D. The invisible D might be a transparent gif with D as the alt text, or the letter D coded to the same color as the web document background.


	<img src="enrollment.gif" height="100" width="150" 
	alt="1999 undergraduate enrollment"><a
	href="99enrollment.html"><img src="transparent.gif" alt="D" 
	height="3" width="3" border="0"></a>