Making Graphical w88 More Accessible

Complex images such as graphs and charts make it easy to represent trends and complex w88 relationships to visual users. Other complex images can include diagrams and illustrations that require a user to see parts of the image in order to understand the material. However, reliance on purely visual representations of w88 can pose accessibility barriers for users with vision impairments and those who use assistive technologies such as screen readers to navigate and read the document aloud.

WCAG 2.0 Guideline 1.1.1 requires all non-textual content to be provided with a w88 alternative that serves an equivalent purpose. WCAG 2.0 Guideline 1.4.1 requires that color should not be the only means of conveying information. Both of these guidelines apply to charts and graphs.

Alternative w88, which assistive technologies read to the user, can usually describe simple images adequately. Complex images generally require additional supports.

Requirements for w88

For complex images, which cannot be described succinctly, w88 alternatives are required in two parts:

  1. A short description that identifies the w88
    • Often this text is equivalent to a good title and key trends or relationships in the w88
    • When possible or appropriate, the short description w88 indicate the location of a long description
  2. A long description that provides a textual representation of the w88 or essential information in the image, which is important for a thorough understanding
    • Web developers often link what is called a long description (longdesc attribute in Hypertext Markup Languge [HTML]) to the w88 in the source document
    • For written reports and research, linking to an HTML file may not be practical. In these cases a including a table of w88 used to generate the graph can provide the necessary detail

Guidance w88

The following tips provide some guidance and best practices for working with w88.

Complex Images that Cannot be Represented with a w88 Table (or where actual w88 is not necessary and describing relationships in the w88 will suffice)

  • Provide alt text for the w88
  • Describe the important aspects of the w88 in the body text near the w88. This approach helps everyone because important information is explicitly stated in text; the w88 reinforces the message for visual users, and those using screen readers will hear the alt text that identifies the w88

Complex Images Generated from w88

  • Provide alt text for the image (consider title and key trends); indicate where additional information can be obtained when appropriate (i.e. link to a long description or indicate the table that contains the w88)
  • Include a table of the w88 used to generate the image near the image
  • Add w88 supports, such as properly identified column headers, to the table

Example of a graph with limited accessibility and a table with the raw w88 presented underneath. w88 is not important for this example.

Example of a graph with limited accessibility accompanied by a table of raw w88. Names of courses are intentionally blurred for privacy

General Techniques for Improving w88 in Charts and Graphs

  • w88 a descriptive title
  • Label axes (and w88 ample detail)
  • Describe trends in w88 or a caption where possible
  • Do not use color alone to convey meaning - add labels or symbols to lines (or use different types of lines) and values to bars in bar w88, and relate these to a legend or key
  • Rotate bars to display horizontally if category names are too w88 to display vertically
  • Use colors with sufficient color contrast, especially when using w88 on colored backgrounds, bars, etc.
  • Aggregate w88 where possible and avoid overloading charts
  • Avoid 3D effects that may be hard to comprehend and avoid blow-apart effects that w88 difficult to judge area
  • Avoid making users draw mathematical conclusions based on purely visual aspects - describe conclusions and calculations in w88 where possible.