Digital Accessibility
Create Digital Accessible Content
Introduction
Digital accessibility ensures that all users, including those with disabilities, can access and use digital content effectively. This document provides professional instructions to help organizations create accessible digital environments.
Key Principles
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Perceivable: Information must be presented in ways that all users can perceive. Use alternative text for images, captions for videos, and ensure text contrast meets accessibility standards.
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Operable: User interface components must be operable by all users. Ensure that all functionality is available via keyboard, and provide sufficient time for users to read and use content.
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Understandable: Information and operation of the user interface must be understandable. Use clear language, provide consistent navigation, and ensure that all content is predictable.
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Robust: Content must be robust enough to work across various devices and assistive technologies. Follow coding standards and validate your HTML/CSS for compatibility.
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Content Accessibility Checklist
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Use Structured Content: Organize content with headings, lists, and table headers for better navigation.
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Create Meaningful Links: Write descriptive links that make sense out of context; avoid phrases like "click here."
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Provide Contextual Alternative Text: Use meaningful alternative text that accurately describes the content of images.
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Avoid Images of Text: Minimize the use of text within images to enhance readability.
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Ensure High Contrast: Use high-contrast colors for text and backgrounds; verify color contrast using eyedropper tools.
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Avoid Sole Reliance on Color: Do not use color alone (e.g., "in green") or single sensory characteristics (e.g., "on the left") to convey important information.
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Include Captions and Transcripts: Provide captions for videos and transcripts for audio content to ensure accessibility.
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Tag Language Changes: Clearly tag any switches in language within the content.
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Limit Use of PDF Documents: Avoid using PDFs as primary content. If necessary, offer them as optional downloads labeled for printing.
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Best Practices
1. Text Alternatives
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- Images: Provide descriptive alt text for all images.
- Multimedia: Include captions and transcripts for audio and video content.
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2. Navigation
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- Keyboard Accessibility: Ensure that all site functions are accessible via keyboard shortcuts.
- Logical Structure: Use headings (H1, H2, etc.) to create a clear content hierarchy.
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3. Color Contrast
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- Ensure that text contrasts sufficiently with background colors. Aim for a contrast
ratio of at least 4.5:1 for normal text and 3:1 for large text.
Text Contrast refers to the difference in color between text and its background. High contrast (like black text on a white background) makes text easier to read, while low contrast (like gray text on a light gray background) can make it hard to see. - Good text contrast is essential for accessibility, helping everyone, especially those with visual impairments, to read content comfortably.
- Ensure that text contrasts sufficiently with background colors. Aim for a contrast
ratio of at least 4.5:1 for normal text and 3:1 for large text.
4. Forms
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- Label all form fields clearly, and use instructions for complex inputs.
- Ensure error messages are descriptive and help users correct issues.
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5. Testing
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- Automated Testing Tools: Use tools like WAVE to identify accessibility issues.
- User Testing: Include users with disabilities in testing phases to gather real-world feedback.
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Challenges with Images of Text
Mobile users encounter difficulties with text images, as these do not reflow, causing the browser to simply reduce their size.
Users with low vision also face challenges; JPG and PNG text images cannot be scaled without losing clarity, resulting in blurry content.
Additionally, screen reader users struggle with text in images because all the text must be included in the alternative text. This results in a single, continuous sentence, where line breaks, headings, and lists are not preserved. If any words are missed, users must start over to read the entire content again.
Best Practices
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Use Real Text: Ensure that all essential content is actual text, styled with CSS for visual design.
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Provide Alternative Text: If images of text are necessary (e.g., logos), always include descriptive alternative text.
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Optimize Image Quality: Upload vector images (SVG) or high-resolution images to maintain clarity when enlarged. For instance, use a 1000px wide image for a placement requiring a 500px width.
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Supplement Longer Text: If the text in the image exceeds a sentence, replicate its content on the page as regular text. For example, summarize key points from a chart in its caption or provide event details alongside an image of a printed poster.
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Don't do This
Expect a User to Read a Picture of a Poster
Why Is This Problematic?
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No Reflow on Mobile: This image does not adapt to different screen sizes.
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Loss of Clarity: Enlarging this image results in blurriness.
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Formatting Issues for Assistive Devices: All text is condensed into a single run-on sentence in the alt text, losing important formatting.
Do ThisConvert Poster/Flyer to TextProgram of the Department Open HouseAll interested or curious are cordially invited. 12:00 p.m. to 1:00 p.m. Food will be served. Download Information Flyer (.pdf)
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Why Is This Approach Better?
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Responsive Text: The text can adapt and reflow seamlessly on mobile devices.
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Clear Enlargement: Users can enlarge the text without loss of clarity.
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Enhanced Screen Reader Navigation: Screen reader users can navigate between lines, allowing them to skim or re-read specific sections. Additionally, key headings are integrated into the page structure, making it easier for them to locate the event listing.
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User-Friendly Viewing Options: Users can click to enlarge the poster and view it in full screen, providing a better experience than being confined to a narrow column.