Chatting to the German newspaper Welt Am Sonntag, Raghavan warned that "This type of artificial intelligence we're talking about can sometimes lead to something we call hallucination… this is then expressed in such a way that a machine delivers a convincing but completely fictitious answer."

Raghavan said the huge language models behind this technology make it impossible for humans to monitor every conceivable behaviour of the system.

He said that Google was considering how we can integrate these options into our search functions, especially for questions to which there is not just a single answer.

"We feel the urgency, but we also feel the great responsibility. We hold ourselves to a very high standard. And it is also my goal to be a leader in chatbots in terms of the integrity of the information and the responsibilities we take. This is the only way we will be able to keep the public’s trust.”

This would all sound reasonable if Raghavan had been saying all this sort of thing when Google’s own AI-based products had been released. Google Translate for example is passable but about as accurate and reliable as Russian artillery. Google was not telling users not to trust it and many companies actually believe they can use it to translate legally sensitive documents.