https://www.theregister.com/2023/03/14/openai_gpt4_ai/
OpenAI acknowledges that GPT-4 "hallucinates facts and makes reasoning errors" like its ancestors, but the org insists the model does so to a lesser extent.
"While still a real issue, GPT-4 significantly reduces hallucinations relative to previous models (which have themselves been improving with each iteration)," the company explains. "GPT-4 scores 40 percent higher than our latest GPT-3.5 on our internal adversarial factuality evaluations."


