The Alt Text Ambiguity
A news website publishes an article about a recent protest. The article includes a photograph of a crowd holding signs, with one sign clearly reading 'Equal Rights Now'. The web developer adds alt text: 'Protesters holding signs'. A screen reader user complains that the alt text is insufficient because it doesn't convey the key message on the sign. The developer argues that the alt text describes the image adequately and that including the sign text would be redundant because the article's text already mentions the sign. The editor disagrees, saying that the image is a powerful visual element and the alt text should capture its essence. The team is divided and asks you to mediate and provide guidance on writing appropriate alt text for this image.
1. What are the key principles for writing effective alt text according to WCAG 2.1? How does context influence the appropriate alt text for this image?
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WCAG 2.1 Success Criterion 1.1.1 Non-text Content requires a text alternative that serves the equivalent purpose. Alt text should be concise, descriptive, and context-dependent. For this image, the context is a news article about a protest. The alt text should convey the essential information the image provides, including the sign's message if it is central to the story. Since the article mentions the sign, the alt text could be 'Protesters holding signs, one reading Equal Rights Now' to avoid redundancy but still capture the key visual. The principle is to ask: what information does the image convey that is not already in the text? If the sign is already described, the alt text might focus on the crowd's size or mood, but it should not omit the sign entirely if it's a focal point.
2. Provide a revised alt text for the image and justify your choice. How would you handle similar images in the future?
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Revised alt text: 'A diverse crowd of protesters holding signs, with a prominent sign reading Equal Rights Now.' This captures the key message and the visual context without being overly verbose. Justification: It includes the sign text because it's a key element, and it describes the crowd to convey scale. For future images, establish a guideline: alt text should describe the image's purpose in context, include text within images if meaningful, and avoid redundancy with surrounding text. Train content creators to consider the image's role and test with screen reader users.