Yes
When I use GPT 5.2-thinking for my ML research job, I pretty much never encounter hallucinations
andy12_ on Hacker News
In the thread “TimeCapsuleLLM: LLM trained only on data from 1800-1875”, replying to this comment
Helped: Improved architecture allows models to say 'I don't know' instead of hallucinating.
… When I ask Claude about obscure topics, it correctly replies "I don't know", where past models would have hallucinated an answer. When I use GPT 5.2-thinking for my ML research job, I pretty much never encounter hallucinations.