EchoAudit Assessing reports from incomplete evidence
Nathan Samson · Team EchoAudit
Submitted to AI Collusion Research Sprint. Sprint projects are early-stage work by participants, not Apart Research publications.
An evidence auditor may receive an invoice report and only part of its supporting ledger. Missing records sometimes prevent a justified verdict, yet the visible subtotal can already disprove a claimed total. We constructed twelve ledger families that separate these situations while holding partial source evidence fixed. Each family supplies an unresolved report, two complete source versions with opposite correctness, and a partial report below the visible subtotal. Three scripted message contexts accompany each view, producing 144 assessments per configuration. Qwen3-8B in nonthinking mode returned valid structured outputs on all 144 calls and accurately assessed 71/72 complete source cases. It gave no warranted abstentions on 36 unresolved cases. None of 36 context pairs combined warranted abstention with rejection of the partial but refutable claim. A subsequently selected Claude Sonnet 5.5 configuration with adaptive thinking received the same instruction and evidence strings on the same families. It accurately assessed 65/72 complete source cases, but only 81/144 responses passed the unchanged output contract. Its joint partial score was 1/36, with 35/36 unresolved responses invalid. These output failures limit a semantic comparison between configurations. The diagnostic separates complete source reconciliation, evidence sufficiency and valid answer production within a small synthetic domain.
Reviews
The U / P- construction is a nice piece of design. Holding the visible records fixed while making one claim unresolved and another refutable from a lower bound cleanly separates "abstain because evidence is missing" from "reject because the visible subtotal already disproves the claim", and blanket abstention cannot game the joint metric. The frozen schedule, planned denominators, and the independent arithmetic check are good practice.
Main limitations and suggestions:
- The link to collusion is thin. The S/T author-label manipulation was meant to be the bridge to coordination, but Qwen's ceiling/floor and Sonnet's invalid outputs leave it uninformative. As written this is an evidence-sufficiency / abstention diagnostic for auditors; consider leading with that framing and positioning the allegation contexts as future work.
- Most of Sonnet's 63 invalid outputs come from extra text after the JSON object or over-long explanations, concentrated on U. A secondary, clearly labeled lenient-parse analysis (take the first JSON object, ignore the length cap) would show whether Sonnet actually abstained, which is the interesting semantic question. Keep the strict result as primary.
- Qwen in non-thinking mode with a 256-token cap may be under-resourced for reasoning about possible completions. A thinking-mode or larger-budget arm would help separate model capability from configuration.
- Twelve families from one invoice template is small. Varying the domain would test whether the abstention failure generalises.
- The report is long and very dense. A short plain-language summary and the headline table near the top would help readers a lot.
Overall a careful, well-controlled diagnostic.
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Cite this project
@misc{samson2026echoaudit,
title = {{EchoAudit Assessing reports from incomplete evidence}},
author = {Nathan Samson},
year = {2026},
month = oct,
note = {Submitted to AI Collusion Research Sprint, an Apart Research Sprint},
howpublished = {\url{https://apartresearch.com/sprints/projects/echoaudit-assessing-reports-from-incomplete-evidence-jj4l}},
url = {https://apartresearch.com/sprints/projects/echoaudit-assessing-reports-from-incomplete-evidence-jj4l}
}More from AI Collusion Research Sprint
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