• Describe the image in the surrounding text. Learners using screen readers will benefit from this placement, but other readers as well. 
• If your space is limited, you can create an appendix that contains the long description. If you go with this option, make sure you link from the original location to the appendix and link from the appendix to the original text. That way, users can easily navigate back and forth between the original text and image and the description. 

Think about what will work best for the learners. If your graph or diagram is too complex, break it up into more easily described images. If the chart or graph is formatted correctly, screen readers will be able to read and navigate the data.  

Connect to Alt-Text 

Even though your long description provides the actual description of the image, you still need to alert screen readers to the image. You also need to ensure that users can make the connections between the image in the original location and the long description. To do this, a two-part text approach is needed. The first part will include a brief snippet of alt-text, identifying the image and (when necessary) the location of the long description. The second part will consist of the long description. 

Check out the example below that shows how to make the connection: