Meaningful Sequence
Summary:
WCAG 1.3.2, "Meaningful Sequence," focuses on presenting content in a logical order that preserves meaning and usability, especially for screen reader users and those who rely on assistive technologies. This guideline ensures that users can comprehend and navigate content even when its visual layout changes.
What:
The criterion requires that when the sequence in which content is presented affects its meaning, that sequence must be programmatically determinable. This means that users must be able to understand and use the content even if it's not presented in the typical visual layout.
Why:
For users who rely on assistive technologies, the visual order of content is often different from the reading order. If the content isn't structured properly, it can lead to confusion and misinterpretation. Ensuring a meaningful sequence is crucial for these users to understand the information correctly and interact with it effectively.
Examples and Scenarios:
- Tab Order in Forms: In online forms, the tab order should follow the logical sequence of the form fields, ensuring a natural progression for users navigating via keyboard.
- Reading Order in Multi-column Layouts: For content presented in columns, ensure that when linearized (read in a single column), the information makes sense in the order it's read.
- Navigation Menus: The items in navigation menus should be organized in a way that retains their meaning when read by a screen reader, independent of visual styling.
How to Comply:
- Websites: Use HTML and CSS to structure and style content so that its order is logical when read by screen readers. Avoid using CSS to visually rearrange content in a way that disrupts the logical sequence.
- Mobile Apps: Ensure the content flow in apps follows a logical order that makes sense when read out of visual context.
- Software Applications: Design the user interface so that elements are navigated in a meaningful sequence, especially for complex interfaces with multiple sections or interactive components.
Exceptions:
- Visual Layout Not Affecting Understanding: If rearranging the sequence doesn’t affect understanding or operation, the criterion may not apply.
- Complex Data or Visualizations: Certain data presentations or complex visualizations where the sequence is not the primary means of understanding the content.