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RAG evaluation scores fluctuate due to LLM judge and generator noise

A recent analysis of retrieval-augmented generation (RAG) systems reveals that evaluation scores can fluctuate significantly between runs due to noise from either the LLM judge or the answer generator. The study found that for faithfulness and answer relevancy, the generator's output variation accounts for the majority of score changes. Conversely, metrics like context recall and precision are primarily affected by noise from the LLM judge, especially when retrieval is deterministic. The findings suggest that to achieve meaningful comparisons, faithfulness scores need to differ by approximately 0.15, relevancy by 0.08, recall by 0.09, and precision by 0.10, based on 18 questions. AI

IMPACT Highlights the need for careful interpretation of RAG evaluation metrics, suggesting that significant score differences are required to indicate genuine improvements.

RANK_REASON The item details a research methodology for evaluating RAG systems and presents findings on score variance. [lever_c_demoted from research: ic=1 ai=1.0]

Read on dev.to — LLM tag →

AI-generated summary · Google Gemini · from 1 sources. How we write summaries →

RAG evaluation scores fluctuate due to LLM judge and generator noise

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The item details a research methodology for evaluating RAG systems and presents findings on score variance. [lever_c_demoted from research: ic=1 ai=1.0]
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  1. dev.to — LLM tag TIER_1 English(EN) · Hua Li ·

    Judge noise or answer noise? What really moves RAG evaluation scores

    <p><strong>Summary.</strong> RAG evaluation scores change from run to run even when nothing in the system changes. I measured where that variation comes from in my own system: from the LLM judge grading the same answers differently, or from the generator writing different answers…