If you think search engines powered by artificial intelligence, such as Microsoft’s Bing Chat, are providing you with useful-sounding answers, it is more likely that they are wrong, researchers have found.

“In these current systems, accuracy is inversely correlated with perceived utility,” says Nelson Liu at Stanford University. “The things that look better end up being worse.”

Microsoft is just one of many companies offering AI-powered search tools, which generate results in digestible paragraphs that cite other websites rather than …