MIT News: “Mixed appraisals of one of the internet’s major resources, Wikipedia, are reflected in the slightly dystopian article “List of Wikipedia Scandals.” Yet billions of users routinely flock to the online, anonymously editable, encyclopedic knowledge bank for just about everything. How this unauthoritative source influences our discourse and decisions is hard to reliably trace. But a new study attempts to measure how knowledge gleaned from Wikipedia may play out in one specific realm: the courts. A team of researchers led by Neil Thompson, a research scientist at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL), recently came up with a friendly experiment: creating new legal Wikipedia articles to examine how they affect the legal decisions of judges. They set off by developing over 150 new Wikipedia articles on Irish Supreme Court decisions, written by law students. Half of these were randomly chosen to be uploaded online, where they could be used by judges, clerks, lawyers, and so on — the “treatment” group. The other half were kept offline, and this second group of cases provided the counterfactual basis of what would happen to a case absent a Wikipedia article about it (the “control”). They then looked at two measures: whether the cases were more likely to be cited as precedents by subsequent judicial decisions, and whether the argumentation in court judgments echoed the linguistic content of the new Wikipedia pages. It turned out the published articles tipped the scales: Getting a public Wikipedia article increased a case’s citations by more than 20 percent. 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 (but not the converse). Unsurprisingly, the increase was bigger for citations by lower courts — the High Court — and mostly absent for citations by appellate courts — the Supreme Court and Court of Appeal. The researchers suspect this is showing that Wikipedia is used more by judges or clerks who have a heavier workload, for whom the convenience of Wikipedia offers a greater attraction.

A paper describing the study is being published in “The Cambridge Handbook of Experimental Jurisprudence” (Cambridge University Press, 2022). Joining Thompson on the paper are Brian Flannigan, Edana Richardson, and Brian McKenzie of Maynooth University in Ireland and Xueyun Luo of Cornell University.” [Open PDF in Browser]