A historic viaduct helper retrieves a 1910 paint recipe when asked about this Saturday’s detour. The final sentence is fluent; the retrieved passage was irrelevant. What should be scored separately?
Select an answer to reveal the explanation.
Short Explanation
Think of asking about Saturday's detour and getting a 1910 paint recipe. Score retrieval relevance, not only how pretty the last sentence is. A fluent line can sit on the wrong page.
Full Explanation
RAG applications need retrieval-relevance evaluation, not only final-prose quality. A fluent sentence can sit on an irrelevant 1910 recipe. Fluency-only, ROUGE-only, or skipping retrieval scores miss that failure.