Let's review. For every image on a page, first determine if it is meaningful or decorative. If the 
image is meaningful, write a short text description between 70 and 80 characters long and 
add that to the Alt attribute within Dreamweaver. If the image is decorative, simply mark the 
image as empty in Dreamweaver. There are some cases where having a short text description 
is not sufficient to describe an image. Fortunately, this does not occur very often, however 
when it does occur, we need to take additional steps in order to make that image accessible. 
The way that we do this is by using the longdesc attribute of the image element. Again, 
because this occurs very infrequently, probably in less than 5% of all images that occur 
within Web pages, it is an uncommon technique, but still important to know. If you run 
into images of this complexity, please contact Web Services at CSUCI and Web Services staff 
would be happy to help you implement the longdesc attribute for your images. The usage of 
the longdesc attribute is as follows: Within the HTML image element, the longdesc attribute 
is added followed by the URL to the Web page that contains the text of the description for the 
image. So let's look at some examples. Here is an example of a diagram that exists on the 
CSUCI Web site. We know that it is a meaningful image because it contains important information 
and there is text embedded within the image. The short text description for this image is: 
Diagram of the conversion from embryo to stem cell. However, you can see with that short text 
description that it doesn't fully describe all of the information that is going on in 
this diagram. Imagine if you were a student that had to understand what was going on in 
this diagram for an exam. Would that short test description be sufficient to understand all of 
the information? Probably not, so in addition to the short text description, we provide a long 
text description. And an example of the way the long text description looks is as follows. 
This is a link to a text file, which simply has the steps that are listed in the previous 
diagram written out as text. This way, the text can be read by a screen reader or other 
assistive technology and understood. Here's another example of a complex image. We 
know the image is meaningful because it contains some text, and the fact that it is a 
diagram suggests that it is meaningful. However, unless you are a biologist, you may not be 
aware of what is going on in this diagram, so there are a few issues here. First, you'd need 
to contact whoever provided or created this diagram to obtain a more meaningful description of 
what this diagram represents. In this case, we'd look at the example listed under right. We 
have the correct usage of both the short text description, which for the previous diagram, 
image number 3, was beta-secretase enzyme as well as the correct usage of the long 
description attribute, which is set equal to a URL to a page that contains a complete text 
description. Notice that the first two examples of the HTML code for the image are 
incorrect. The first example is incorrect because it is missing both the short text description 
and the long text description. The second example is incorrect because, although it contains a 
short text description, the meaning of the short text description does not apply to 
the diagram. We are looking at a diagram of a beta-secretase enzyme, not a diagram of hands 
on a soccer ball. For more complex images, please refer to the following Web pages as 
reference or contact the Web Services office for assistance in describing complex images, 
charts or diagrams.