Irish judges are using Wikipedia as a source for their rulings, a major academic experiment has found, prompting fears the internet encyclopaedia could be manipulated to influence decisions.
Researchers at Massachusetts Institute of Technology (MIT) and Maynooth University created 154 articles on Irish Supreme Court decisions, half of which were uploaded to Wikipedia.
They discovered the cases detailed in the uploaded articles were 20pc more likely to be cited as precedents in court rulings than cases dealing with similar issues that were not uploaded.
Not only did researchers find that Wikipedia was influencing judges’ legal reasoning, but an analysis of the language used in judgments found the “linguistic fingerprints” of the Wikipedia articles.
One of the main researchers and a co-author of the paper, Maynooth associate professor of law Brian Flanagan, said: “It is not cut and paste but they are using phrases and terms that could only have come into their head if they were just after reading the Wikipedia summary.”
Dr Flanagan said the discovery was worrying, because the articles could have been written by people with no legal training or someone involved in the case that was being decided. “There is no way of knowing,” he said.
“A well-resourced litigant could encourage his legal team to anonymously integrate their own analysis of a relevant precedent into a Wikipedia article at an early stage of litigation in the hope of later attracting the attention of the judge or his clerk.
“It’s difficult to quantify the risk of such a practice. But given known trends in online misinformation and the relative openness of Wikipedia’s content to general internet users, it is possible to imagine scenarios in which it might surface.”
A paper on the research, which took five years to conduct, is due to be published today. Researchers concluded that having a Wikipedia article about a Supreme Court precedent tipped the scales in favour of that case being cited.
They found the increase was statistically significant, and the effect was particularly strong for cases that supported the argument the citing judge was making in their decision.
The issue was most common in High Court judgments and was largely absent for citations of precedent in Court of Appeal and Supreme Court.
This led researchers to suspect that Wikipedia was being used more by judges or clerks who have a heavier workload, as would be the situation in the High Court.
Researcher and co-author Neil Thompson, of MIT’s Computer Science and Artificial Intelligence Laboratory, said previous studies showed Wikipedia influenced low-stakes decisions, such as tourism choices, and some higher-stakes, but less formal decisions, such as what appears in scientific journals.
“This work shows that Wikipedia reaches even farther than that, into high-stakes, formalised processes like legal judgments,” he said. “The worst outcome would be for a judge’s reliance on Wikipedia to lead them to decide a case differently than they would have if they had read either an expert secondary source or the cited precedent itself. Even without any difference in outcome, however, judges’ reliance on Wikipedia to determine the applicable law undermines the litigant’s expectation that the court’s reasoning is the product of expertise alone.”
The apparent reliance on Wikipedia comes as the Government is under pressure to increase the number of High Court judges. The former president of the court, Mary Irvine, said when she retired earlier this month that 17 or 18 extra judges were now needed .