October 31, 2024
Web accessibility overlays are intended to let users control visual elements like font size, color, and contrast. Recent research found that these attempts to make inaccessible sites accessible often interfered with screen readers and drove users away from the sites.
Kristin Shinohara, Ph.D. iSchool ’17, co-authored a paper that indicates web overlays failed to make sites accessible and provided the following summary. Shinohara, who was advised by CREATE associate director Jacob O. Wobbrock and co-advised by CREATE faculty Wanda Pratt, shared the following summary of the academic paper.
The Promise and Pitfalls of Web Accessibility Overlays for Blind and Low Vision Users
Published at ASSETS 2024 (ACM Digital Library Link). Authors: Tlamelo Makati, Technical University Dublin; Garreth W. Tigwell, Rochester Institute of Technology; Kristen Shinohara, Rochester Institute of Technology.
Web accessibility overlays are web-based tools implemented to adjust the front-end code of a website to allow users to control presentation elements, like page presentation, font size, and color, among other things. We investigated user experiences with accessibility overlays through a survey and interview study with blind and low vision web users.
We found that accessibility overlays often failed to deliver on the aim of making web pages accessible. As many as 42% of survey respondents stopped using websites with overlays, the most common reason being the site was less accessible than before the overlay was implemented.
The most prominent access issues were layout and page navigation, such as being unable to use a screen reader to search page information. Other reasons for abandonment included slow, buggy page access and disruptive prompts. Survey respondents overwhelmingly indicated that overlays were “not at all effective” in making websites accessible, and they visited websites less frequently than before the overlays were implemented.
A bar chart from the paper shows how study participants rated an overlay tool’s effectiveness:
- 3 users called it “very effective”
- 7 users rated it “somewhat effective”
- 8 users rated it “not very effective”
- 16 users rated it “not at all effective”
Interview findings further detailed issues, for instance, that overlays often created accessibility barriers when superficial “fixes” conflicted with assistive technology tools already in use. For example, overlays with a screen reader mode clashed with users’ screen reader, making it difficult for them to access content on the page. The prevalence of these issues across many websites was frustrating, especially when overlays blocked access to compulsory sites, such as utility companies.
Though some participants benefited from minor accessibility adjustments afforded by overlays (such as adjusting font size or color contrast), participants were also knowledgeable in website design and use, and noted that overlays were an example of business case superseding usability and functionality. Specifically, participants acknowledged and companies used overlays because they thought overlays would meet compliance goals. Some participants also acknowledged the potential benefits of scalable updates. However, overlay usability and accessibility issues limited any potential benefits.
Our work highlights the key role good web design plays in making websites accessible, and underscores the perils of accessibility overlays if they are not functionally accessible to the user.