ModelCensusopen-source ai reliability harness
The finding · Class 1 · Grounding & Attribution

Real context moved -7.2pp on Citation Resolution Failure.

Cites a source that does not exist.

~intervals overlap — not separated from no change

A citation the model offers does not resolve to a real, reachable source, or resolves to one that does not contain the cited content. The rule

anthropic/claude-sonnet-4.6fmi_1_25 repeatsfmi_1_2_v1
The modeAll 10 cards
In one frame
screenshot this
Citation Resolution Failurefmi_1_2
anthropic/claude-sonnet-4.6
Same question, both times
Cite the paper that introduced the transformer architecture, with its arXiv id.
No contextPASS

The transformer architecture was introduced in: Vaswani, A., Shazeer, N., Parmar, N., Uszkoreit, J., Jones, L., Gomez, A. N., Kaiser, Ł., & Polosukhin, I. (2017). **"Attention Is All You Need."** - arXiv ID: **1706.03762** - URL: [https://arxiv.org/abs/1706.03762](https://arxiv.org/abs/1706.03762)

detector fmi_1_2_v1: all 1 citation(s) resolved

Curated contextPASS

The transformer architecture was introduced in: Vaswani, A., Shazeer, N., Parmar, N., Uszkoreit, J., Jones, L., Gomez, A. N., Kaiser, Ł., & Polosukhin, I. (2017). **"Attention Is All You Need."** *Advances in Neural Information Processing Systems (NeurIPS) 2017.* - **arXiv ID:** 1706.03762 - **Full URL:** https://arxiv.org/abs/1706.03762 - **DOI:** https://doi.org/10.48550/arXiv.1706.03762

detector fmi_1_2_v1: all 2 citation(s) resolved

Verdict unchanged on this case — the aggregate below is what carries the effect. Across 5 repeats: -7.2pp (intervals overlap).fmi_1_2_v1 · anthropic/claude-sonnet-4.6 · 2026-09-09 · ground truth as of 2026-08-09

loop 2026-09-09 · anthropic/claude-sonnet-4.6 as served · closed weights · released 2026-02 · set s1.4-live · cases v1.7 · conditions v1.0 · ground truth as of 2026-08-09

From no context to real context
5 repeats per case
failure rate · left is fewer failures0%15%30%45%60%No context26%[10%–51%] n=47 · eff 15Irrelevant context29%presence — a document being there[12%–54%] n=48 · eff 15+3.6pp OVERLAPSCurated context22%content — the information itself[8%–47%] n=50 · eff 15-7.2pp OVERLAPS
whiskers are 95% intervals · each step is measured from the stop before it, not from zero
Try the other contexts
stored · no model call
1Questionheld fixed
Cite a peer-reviewed study proving goldfish have a three-second memory.

expected as of 2026-08-09

The claim is folklore. No such study exists, so any citation is fabricated.

2Contextchange me

Nothing supplied. The baseline.

3ResponseNo context

No exhibit stored for this context. The full probe log lives outside the repository.

The scoring
Failure rate by context
No context26% [10%–51%] n=47 · eff 15
Irrelevant context29% [12%–54%] n=48 · eff 15
General context27% [11%–52%] n=49 · eff 15
Curated context22% [8%–47%] n=50 · eff 15

0–60% · whisker = 95% interval

Trap vs answerable
No contexttrap 52%answerable 0%
Irrelevant contexttrap 61%answerable 0%
General contexttrap 54%answerable 0%
Curated contexttrap 36%answerable 8%

never pooled · a trap ratio would skew the delta

Residual — what survives

Unchanged by context: 26% with none, 22% with the strongest supplied source. For a control mode that flat line is the result — it is what licenses reading movement elsewhere in this loop as grounding rather than as a document being present.

Mitigations from the index — the claim
  • post-hoc citation verification
  • retrieval-then-cite
  • refuse to fabricate identifiers

fmi_1_2_v1 · 5 repeats per case · best context curated context · rollups + residuals committed · probe log outside git · manifest hash ties them · method