Skip to content
aiqbench takeAI Research

aiqbench analysis

This paper introduces Agent Step Value (ASV) to audit how step rewards in black-box agents fluctuate when evaluated across different channels, revealing significant instability where cross-channel gain signs disagree nearly half the time. By isolating state-by-channel interactions in frozen PubMed QA tasks, the authors demonstrate that generated support artifacts can inflate pre-retrieval baselines, offering a method to localize these sensitivities before rewards are reused. This work provides a critical diagnostic tool for improving the robustness and reliability of agent evaluation pipelines.
Source coveringarXiv
What this isA model's reading of the article and related coverage, written for aiqbench. Not the publisher's words.

Agent Step Value: Auditing Evaluation-Channel Sensitivity in Black-Box Agent Traces

arXiv2 min read

arXiv:2607.04419v5 Announce Type: replace Abstract: Reusing evaluator-derived step rewards across evaluation channels raises a measurement question: does the assigned direction remain stable? We define Agent Step Value (ASV) as a channel-indexed before/after target-margin gain and identify the state-by-channel interaction from a matched 2x2 design. Across frozen PubMed question-answering transitions, cross-channel gain signs disagree on 48.3% of comparisons, compared with 0.3% for same-channel retries. Transition interactions are nearly balanced in sign (median +0.014; 10% trimmed mean -0.033), but asymmetric negative magnitudes produce a positive direct mean and a negative generated-view mean under the empirical target mixture. Equal-target weighting preserves a negative mean interaction but not this strict mean reversal. Matched retrieval designs localize the negative component to the generated-view coordinate and retain its direction across three sign checks that vary readout and evaluator stack. In a matched 512-token source-contract follow-up, source-only generation restores the positive mean direction on artifact-bearing retrievals and removes parser-detected support claims from artifact-free before-state views. These results support an explanation in which generated support inflates the pre-retrieval baseline. The resulting audit can localize channel sensitivity and test an intervention before step rewards are reused.

Abstract:Reusing evaluator-derived step rewards across evaluation channels raises a measurement question: does the assigned direction remain stable? We define Agent Step Value (ASV) as a channel-indexed before/after target-margin gain and identify the state-by-channel interaction from a matched 2x2 design. Across frozen PubMed question-answering transitions, cross-channel gain signs disagree on 48.3% of comparisons, compared with 0.3% for same-channel retries. Transition interactions are nearly balanced in sign (median +0.014; 10% trimmed mean -0.033), but asymmetric negative magnitudes produce a positive direct mean and a negative generated-view mean under the empirical target mixture. Equal-target weighting preserves a negative mean interaction but not this strict mean reversal. Matched retrieval designs localize the negative component to the generated-view coordinate and retain its direction across three sign checks that vary readout and evaluator stack. In a matched 512-token source-contract follow-up, source-only generation restores the positive mean direction on artifact-bearing retrievals and removes parser-detected support claims from artifact-free before-state views. These results support an explanation in which generated support inflates the pre-retrieval baseline. The resulting audit can localize channel sensitivity and test an intervention before step rewards are reused.

Accepted at the REALM Workshop @ EMNLP 2026 (2nd Workshop for Research on Agent Language Models). 16 pages, 5 figures. The two authors contributed equally

Artificial Intelligence (cs.AI)

arXiv:2607.04419 [cs.AI]

(or arXiv:2607.04419v5 [cs.AI] for this version)

Full text under the publisher's open licence · 218 words

Related coverage