In 2026, a "hallucination rate" is just a number until you define the stress...

https://lukasnpyy234.cavandoragh.org/claude-vs-gpt-which-is-better-at-admitting-i-don-t-know

In 2026, a "hallucination rate" is just a number until you define the stress test. Use Vectara’s HHEM for retrieval fidelity or AA-Omniscience for deeper reasoning, and you’ll get wildly different results