6 Chapter 6: Testing and Evaluating Alt Text
Ensuring Alt Text effectively conveys the intended information and enhances accessibility requires testing, feedback, and ongoing refinement. This chapter reveals the methodologies and tools available for evaluating Alt Text, alongside strategies for incorporating user feedback and adopting continuous improvement practices to increase digital accessibility.
Tools and Techniques for Testing Alt Text Effectiveness
Screen Reader Software: Utilizing screen readers like JAWS, NVDA, or VoiceOver is fundamental in testing how Alt Text is interpreted and conveyed to users. Simulating the user experience can reveal if the Alt Text adequately describes images and works smoothly with the content.
Accessibility Evaluation Tools: Web accessibility evaluation tools, such as WAVE, Axe, and Google Lighthouse, offer automated checks that can identify missing or potentially inadequate Alt Text, among other accessibility issues. While these tools provide a good starting point, they cannot fully assess the quality and context-appropriateness of Alt Text.
Wave: WAVE Web Accessibility Evaluation Tools (webaim.org)
Axe: Accessibility Testing Tools and Software (deque.com)
Google Lighthouse: Lighthouse (google.com)
Gathering Feedback on Alt Text
User Testing with Diverse Participants: Conducting user testing sessions with participants who rely on screen readers can offer valuable insights into the effectiveness of your Alt Text. Observing how users interact with content and listening to their feedback can aid in improving how Alt Text is crafted.
Accessibility Audits: Regularly conduct accessibility audits that include a focus on Alt Text. These audits should be part of a broader strategy to ensure all aspects of digital content meet accessibility standards.
Training and Awareness: Invest in ongoing training for content creators and developers on the importance of Alt Text and up-to-date best practices. Staying informed about new tools, techniques, and guidelines is crucial for maintaining accessibility standards. Aim to work with an internal/external Accessibility Specialist at your organization who is familiar with WCAG, and accessibility policies and procedures.
Policy and Documentation: Develop and maintain internal guidelines and policies on digital accessibility, including specific standards for Alt Text. Documenting successful strategies and examples can serve as a valuable resource for your team.
Case Study
It is tremendously important to have detailed and context-specific Alt Text, especially for multimedia content. The following case highlights how direct feedback from users who rely on screen readers can lead to meaningful improvements in digital accessibility.
During a recent accessibility audit conducted for a Learning Management system/platform, user testing sessions were organized with participants who rely on screen readers, including students with varying degrees of visual impairments. One of the key findings from these sessions was related to a series of instructional videos on the platform. While each video had alt text for its thumbnail and descriptive transcripts available, participants noted that the Alt Text for some thumbnails was too generic (e.g., “instructional video”), failing to convey the specific topic or content of the video.
Based on this feedback, the instructional design team revisited the Alt Text for video thumbnails on the platform. They revised the Alt Text to include more descriptive and informative content, such as “Video on Photosynthesis Process in Plants” instead of just “Biology Video.” This change significantly improved the navigability and usability of the platform for users with visual impairments, as they could now make informed decisions on which videos to engage with based on the thumbnail descriptions alone.