Complex images and Long descriptions can seem overwhelming at first, but if you follow the advice in this section they will become easier.

We create longer, complex descriptions for any image that contains complex information or data. Common examples are Maps, Graphs, Charts and Diagrams. We can also create longer, complex descriptions when we need to transcribe an Image with Text, such as an image of a letter. If you are not sure if your image requires a complex description, ask in the Q&A section.

A complex image is any image that contains complex information or data. Common examples are Maps, Graphs, and Charts. All complex images require extended descriptions beyond the Alt-text, also known as Long Descriptions.

A Long Description is a detailed text description of an image that can be several paragraphs long and/or may contain other elements such as tables and lists.

When creating a complex description work from the general to the specific: provide an overview of the image before you describe specific details. The way you introduce a complex image can vary depending on the type of image. We included documentation for all the most common images we come across at the end of this page.

For images that require more complex or extended descriptions we create two descriptions:

1. Standard Alt-text in the Alt-text description Box (2-3 sentences average) including See the link below the image for an extended description. at the end of the description
2. Long description in the Complex Image Descriptions Section that links back to the image being described.

Remember to include a basic Alt-text description for the image itself along with a note that the reader can find a longer description in another location of the book. Simply enter the sentence See the link below the image for an extended description. at the end of the Alt-text. This way readers are aware there is a longer description.

We also do this because all non-decorative images require Alt-text, even if a long description is also provided. Empty Alt-tags in non-decorative images can be confusing to the reader, and leave out part of the experience of reading.

Below is a video that shows how a screenreader interacts with a long description:

When creating a complex description work from the general to the specific: provide an overview of the image before you describe specific details. A good strategy is to break the image up into its component parts, and then organize them so that the description makes logical sense.

The complex descriptions must also follow the standard Alt-text guidelines (though it will be longer than 2-3 sentences).

• Breakdown the image into smaller parts and organize it in a logical order (you may have to experiment with which technique works best: Quadrant, Compass, or Clock. See below for more details about breaking down an image.)
• Start with a brief description, followed by more specific information. This allows the reader to get the initial concept and read further if desired.
• Be consistent and balanced in your descriptions. Most long descriptions are not narrative and are more repetitive than general Alt-Text. This helps the reader keep track of the data and information without getting lost.

• Know your audience. If it is a fantasy novel map, a more narrative style would work for the description. But if it is a map in a textbook, then a be less narrative focusing on the data and facts.
• Details are important and so is consistency in terminology across all images in a book or chapter (you can pull terminology from the surrounding text).
• Focus on the data and not on extraneous visual elements. Don’t describe every detail.If the visual elements are important to understanding the image, then describe what they stand for instead of their shape. For example, a dotted line could represent a railway, so state it is railway instead of describing the line.
• If a graph, chart, or other type of visualization has an intentional visual impact, you should include that in your description, just don’t get bogged down or lost in the details.
• Use multiple modalities when necessary. Some content is better converted to tables or lists than being provided in a narrative description.
• The reader should be able to understand the description in one reading. If you organized it properly, they will be able to navigate back and forth through the data with confidence.

A strategy we use is to break the image up into its component parts, and then organize them so that the description makes logical sense.

There are a couple of techniques you can use to breakdown a complex description:

• Quadrants: divide the image into 4 quadrants. Top and bottom, left and right.
• Compass: divide the image by North-South-East-West. This is most commonly used for Maps.
• Clock: divide the image by the times of a clock. This is most commonly used for images that have the main focus in the center of the image.

The type of breakdown will depend on the context, audience, and type of image. Sometimes you will have to experiment with which one works the best for your complex description. By breaking down a complex image into sections you can take the reader on a journey. Remember, you need to be able to walk your reader through the image in a logical order, and you need to be able to recreate the image without looking at it. Using this approach helps to create an immersive experience for the reader. Editing will be important with complex images, go to Editing Alt-text for more information.

Organization of data and information is paramount. Often this requires multiple modalities.

Common usage of multiple modalities:

• Graphs, Charts, Trees (and other data heavy images) will require a link to an accessible table of the data.
• Diagrams, Science Illustrations, Paintings will most likely require a link to a list of the data or information in the image. (Note: You need to do more than simply make a list. You need to include relational information.)
• Maps, Complex Painting and Illustrations will usually require paragraph breaks, but sometimes can use lists. This depends on the context.

Multiple modalities can really help with organizing the informational structure of the image in a way that will avoid cognitive overload.

Multiple Modalities can include:

• Tables
• Lists
• Paragraph breaks
• Even subheadings

It is very important that the describer understand what they are describing, especially for educational resources. If they get something wrong, then the student and reader will get it wrong as well.

Word choice is paramount. Be consistent.

Using the surrounding text the describer will be able to pull terminology for their descriptions. You can also use the dictionary for terms, but if you are working in an educational book the terminology should be found in the surrounding text.

Track terminology used, any progression in the image types, and be consistent with terminology. For example, when a simple image is introduced earlier in the book, and then reintroduced later with more details.

The following sections go do a deeper dive for particular image types that we commonly come across in our work.

• Anatomy and Diagrams with Labels
• Flowcharts and Trees
• Graphs and Charts: Instructions for all types of Graphs and Charts with our most common examples: Bar and Pie Charts
• Maps
• Paintings
• Venn Diagrams

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