To assess whether Wikipedia impacts judicial decisions, the researchers set out to test for two types of influence: (1) whether the creation of a Wikipedia article on a case leads to that case being cited more often in judicial decisions; and (2) whether the text of judicial decisions is influenced by the text of the corresponding Wikipedia article.
Scientists Conclude that Wikipedia Influences Judges’ Legal Reasoning
They found that the addition of a case to Wikipedia increased the case’s citations by 20%.
They also purport to demonstrate with natural language analysis that “a textual similarity exists between the judicial decisions and the Wikipedia articles.”
I’m skeptical that this method proves actual influence by a Wikipedia article. But it’s easy to believe that case salience would have an impact.