The old expression “a picture is worth a thousand words” can be applied to modern digital content just as readily as it is to books or holiday Kodak photos to bore the neighbors.
Content, whether in print or digital form, is more than just paragraph text: content creators employ images, tables, graphs, maps, and other representations to supplement text.
They can be decorative or informative and appear in technical, educational, and literary documents.
However, as with text content, all such non-text content must be accessible to users with disabilities. Users with visual, mobility, or cognitive disabilities need to be able to identify, navigate, and benefit from this content, just as with text.
Let’s consider some measures that can be applied to non-text content.
(Note that we will not discuss video content in this article. That is a separate topic that we will address in a separate blog post.)
Images
Photos, artwork, diagrams, illustrations, pictures of bar graphs, and chart graphs are all examples of images that may need to have alternative representation for people with disabilities.
While it may seem that this content would be detrimental to people with visual disabilities, images are an excellent way to communicate a variety of information, and this information can usually be represented in alternative text for users with visual disabilities.
HTML and PDF documents utilize images with embedded alternative text, abbreviated “alt text,” that encapsulates the meaning of these images.
There are limits to alt text: it should not be particularly long (hence “encapsulate the meaning”), as screen readers have difficulties parsing it and may bypass part of it.
Therefore, complex images (for example, of a bar chart or an anatomical diagram) may require some additional representative text.
This could be screen reader-only text that is invisible to sighted users or visibly represented.
Text within images—whether labeling in a diagram or prominent banner text—should be readily perceivable by users with low vision or color vision disabilities. This includes a few considerations.
The graphic text needs to have sufficient color contrast against the background.
The mathematical contrast ratios for different kinds of text and against different backgrounds are detailed in the Web Content Accessibility Guidelines (WCAG).
In addition, text within images needs to be scalable, such that when magnified, it will maintain as much detail and clarity as possible.
Another consideration is where the image is strictly decorative. Examples include visual flourishes and decorative artwork.
Due to the difficulty in defining accurate representative alternative text, you may decide that the less confusing course of action is to hide these images from being read by screen readers.
In HTML, this is done by providing an empty “alt” attribute; in PDF documents, this is done by “artifacting” the content.
Deciding to do so is often a subjective decision as to which image is decorative rather than informative.
Tables
Tables are grid-like representations of information, where the information can be represented in categories.
These categories take the form of “headers,” which can be either present as one or more rows of column headers or as columns of headers at the start of each row.
An example of a common data table is a calendar: the days of the week are typically in a row at the top of each month, with each day, its number within the month, and any event details present below.
In digital documents such as HTML or PDF, there are ways to present either visible or invisible information about the table and its data.
For example, adding captions to summarize the table contents and mark up the row and column header cells is possible. This helps screen reader users identify the extent of the table and how information within it is categorized.
This helps represent the relationships about the information that is otherwise available visually, such as the scope or range data that any header applies to.
Another important consideration for digital documents is ensuring their width is controlled proportionally to the document.
This matters for users with low vision or cognitive disabilities, as it minimizes the amount of horizontal scrolling required, which can lead to difficulty navigating or orienting within the document.
For print documents that cannot rely on the same invisible information, it is important to provide clear, high-contrast table elements so that users with low vision or color vision deficits can readily interpret the content.
This includes visually distinguishing all headers, providing readily discernable cell borders, and visible table captions where appropriate.
Ensure the table does not rely solely on color to communicate information (such as status).
Maps
Maps can present significant challenges to people with disabilities, as they include multiple visual information types.
These can include community names, political boundaries, geographic features, and topographic information, to name a few.
These types are represented in maps by text (horizontally, vertically, or along diagonals), color, and illustrative elements, including lines and curves.
Rendering maps that are fully accessible can be very difficult. Making alternative versions of maps can include steps such as:
- Providing long text descriptions of the purpose of the map and important features,
- Using high-contrast colors.
- Avoid using color shading to differentiate significant sections of the map—instead, use high-contrast visual borders where possible.
If the map is part of an online application, ensure that:
- Map images have a brief but accurate alternative text description.
- The map and any controls are keyboard-accessible,
- Actual text, rather than graphic text, is used to label the map (if possible).
Whenever possible, make a larger version of the map available in both digital and print documents. This could be via a link to a larger version or on request by the user.
We have touched on some, but not all possible, instances of non-text content. Thankfully, this is not the extent of our familiarity with this topic.
Allyant has a well-deserved reputation as a “one-stop-shop” for accessible communications. As such, we have extensive experience in defining, remediating, and consulting on non-text content.
This includes instances within print documents and digital applications, with clients ranging from governments to educational institutions to banking.
We understand the importance of non-text content, how it can supplement surrounding text, and how to best address the accessibility needs of the public or customer base.
If you have any questions or requirements regarding the accessibility of images, tables, diagrams, charts, maps, or similar content, please reach out to Allyant by submitting the form given below:
