The majority of the world's Google searches have already been searched, but new, ambiguous queries can cause hiccups. To get a better handle on those, the company has quietly enlisted the help of a new AI system: RankBrain.

Bloomberg, reporting on the new AI, writes that a "very large fraction" of searches in the past few months have been answered by the system. About 15 percent of searches sent daily haven't been seen by Google before, and RankBrain is reportedly useful in answering those queries.

"The other signals, they're all based on discoveries and insights that people in information retrieval have had, but there's no learning," Greg Corrado, a senior research scientist at Google, told Bloomberg.

RankBrain is reportedly also more effective at sussing out the meaning behind complicated, ambiguous queries. As an example of an ambiguous search, Bloomberg cites questions like, "What’s the title of the consumer at the highest level of a food chain?"

Google uses hundreds of "signals" designed to bring users the most useful search results, of which RankBrain is only one. But according to the company, it's already turned out to be inordinately effective, becoming the third-most important signal contributing to results.