How do you programmatically check if an LLM is making things up that aren't in the provided search results?

Explain the concept of using a "Stronger" model (like GPT-4o or Claude 3.5 Sonnet) to grade a "Weaker" model’s output. What are the risks of "Self-Preference Bias" in this setup?

When would you evaluate a model without having a "correct" answer to compare it against? (e.g., checking for tone or politeness).

How do you measure "Time to First Token" (TTFT) vs. "Total Runtime"? Which one matters more for user experience in a chatbot?