In 2005, the Irish Supreme Court ruled in favor of a woman who sued a landowner for compensation in 1997 after she lost her footing while watching the sunset and tumbled over a cliff edge, breaking numerous bones in the process.
The ruling, which has since been cited in numerous other legal decisions in Ireland, is neatly summarized in the Wikipedia article Geraldine-Weir-Rodgers vs SF Trust. But that entry was not created by an amateur legal buff. It was written as part of an experiment designed to test how the crowdsourced encyclopedia may influence legal cases.
Edits made to Wikipedia pages can, it turns out, influence some legal rulings.
A team of researchers from Maynooth University in Ireland, MIT, and Cornell University conducted a controlled experiment by creating more than 150 new Wikipedia articles covering Irish Supreme Court decisions, and they chose half of them at random to post to the site. Like the US or UK legal system, Irish courts have a hierarchical structure, with decisions made in higher courts binding rulings made lower down. There were also relatively few Wikipedia articles about Irish Supreme Court decisions at the outset of the experiment.
The team found that the published Wikipedia articles increased the number of citations of a given legal ruling by 20 percent. The citations most often came when they supported the argument a judge was making in a decision. They also used computational techniques to compare the language in judges’ rulings, finding patterns that suggested judges borrowed from the text on the Wikipedia pages they read.
“You have judges deciding what’s going to happen to people—very serious things—and we expect them to use expertise when they do that,” says Brian Flanagan, an associate professor at Maynooth University. In a worst-case scenario, he says, the editor of an article might even have an interest in a case. “The authorship of the Wikipedia articles is effectively opaque,” he adds.
Neil Thompson, a research scientist in MIT’s Computer Science and Artificial Intelligence Laboratory involved with the work, previously looked at how edits to Wikipedia influence citations in scientific journal articles. He says it is troubling that expert knowledge and critical decisions can be swayed by edits of questionable origin. “As you get to more specialized knowledge, it becomes more and more important to have someone who really has a deep understanding,” Thompson says.