Muhammad Ali Gulzar’s research team wasn’t looking for a quirk in digital advertising systems that exploits screen reading technologies and could lead to accessibility violations for web developers. But the discovery could improve the lives of more than 2 billion people worldwide and help website developers make their content more accessible.
Haddi Amjad, a doctoral student in the Department of Computer Science, will present the team’s project, “Accessibility Issues in Ad-Driven Web Applications,” at the International Conference on Software Engineering in Ottawa, Ontario, Canada, on May 2.
It’s the first large-scale investigation of 430,000 website elements, including nearly 100,000 ads, for accessibility and privacy, said Gulzar, assistant professor of computer science in the College of Engineering.
The researchers found that:
- 67 percent of websites that use popular ad-serving technologies had increased violations of international standards and U.S. laws governing online access for disabled users.
- 27 percent of digital ads that did comply with the standards included misleading and potentially deceptive content.
- Digital ads can exploit the gestures required to use screen reader technologies to collect sensitive data without user permission.
- Websites that rely on ads to keep their content online can’t fix these problems; only digital ad companies can.
The work has resonated. The paper was accepted at a top-tier conference. Along with it, Gulzar’s team has published an open access tool that website creators can use to check the accessibility of the ads on their sites.
“It feels amazing that one of my papers got accepted at this conference on the first attempt,” Amjad said. “But the biggest motivation is that the impact of this work is huge. We’re going to do a second project to deliver a solution.”
More than 2 billion people worldwide have a vision impairment, according to the World Health Organization. And many of them use screen readers — technologies that read the text on websites and apps out loud, providing these users with crucial access to web-based information, education, employment opportunities, and social interaction.
Simultaneously, web-based businesses, such as news sites, rely on third-party digital advertising to keep their content online.
Neither affected group can simply opt out of these systems, but they come with downsides.
An unanticipated discovery
Together, Amjad and Gulzar have been working on internet privacy for nearly five years. Another co-author, graduate student Muhammad Danish, worked with the team for three months.
“We started off looking at this problem mostly from the perspective of privacy for general web users,” Gulzar said. “We built systems that allow us to detect any privacy violations on a web page and collected a large data set about online ads, specifically, because ads are the most common way that companies track users and gather information on their interests and likes.”
During one of their recent projects, Amjad and Bless Jah, a graduating senior in the Bradley Department of Electrical and Computer Engineering working with the team, noticed something unexpected.
They found evidence that many third-party digital ads do not comply with accessibility standards required by the Americans with Disabilities Act and other federal laws. The alternative text that describes images to users with a visually impairment is often missing and the close button is too small for those users to locate. The ads also were collecting information about screen reader users who were merely viewing, but not clicking on, the ads on websites.
Jah, under Amjad and Gulzar’s supervision, used screen readers to test the ads and sites manually.
“I would hover over a section of a site to get the screen reader to work, and on the other side of my screen, I could see the ads sending requests for my user information,” Jah said.
“The core issue here is that a person without a disability can look at all of the information and not trigger the ad tracking, but an individual who has visual impairments will have to compromise their privacy just to locate and access information on the web,” Gulzar said.
On the flip side, when ads fail to provide accurate alternate text for screen readers, visually impaired users don’t have the option to interact with that content and instead encounter blank spaces.
“And web developers have no control over these issues because the ads are delivered to users individually by ad-serving technologies and not by the website,” Gulzar said. “Only the advertising companies can fix it.”
After some exploratory work and funding from the Commonwealth Cyber Initiative, Gulzar greenlit the accessibility project.
Security experts often recommend that web developers do away with ads to increase privacy for their users, Gulzar said. But news and other companies that rely on advertising can’t ban ads from their pages and continue to provide content and services for free or at reduced cost.
In addition to the online tool they’ve already developed, the team is considering a second project that could help mitigate these negative impacts for visually impaired internet users and web developers.
“We really want to deliver something as a solution to the community,” Amjad said.
By Tonia Moxley