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Evaluator

As explained in The Art of AI Product Development

LLM-as-a-Judge is an evaluation technique in which a large language model assesses generated outputs against specified criteria.

An LLM-as-a-Judge uses a powerful language model to assess generated outputs against criteria. In a retrieval-augmented generation (RAG) app, it can help scale end-to-end evaluation, complementing component-level tests. section 7.3.2

For a generated response, assess:

  • Groundedness: whether claims rely on the retrieved documents rather than speculation or hallucination. section 7.3.2
  • Answer relevance: whether the response meets the query’s requested focus and depth. section 7.3.2
  • Instruction adherence: whether a fine-tuned model follows the given prompts. section 8.2.3

Evaluating a generated report

For a report on AI trends in SaaS, a judge checks whether the response is supported by retrieved sources and whether it gives the depth the user requested. For instruction fine-tuning, a judge can score adherence on a held-out 20% test set. section 7.3.2 section 8.2.3

Treat judge scores as one part of evaluation: manual audits and user feedback also help identify recurring issues. Keep criteria responsive to real use, and add emerging concerns such as style or tone with oversight. section 7.3.2 section 8.2.3

How The Art of AI Product Development covers it

How deep it goes
Defines groundedness and relevance criteria, then applies model scoring alongside manual audits and user feedback.
Examples
Tests a SaaS-trends report for grounding and relevance and scores instruction adherence on a held-out 20% test set.
What you can do after
Evaluate generated answers for source grounding and query relevance, or score how well a fine-tuned model follows instructions.
How it connects
Connects retrieval-augmented generation, prompt evaluation, instruction fine-tuning, manual audits, and user feedback.

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