qa(verify): Rule 9 — SUBJECT_TOKENS_ABSENT premise-parroting demote

Closes the first confirmed EVIDENCE-WARRANTED false-positive
surfaced by the 200-cycle bench-emergent run on
`steer/reply/correcter` (Ticket #000006 amend 2026-05-02b). The
model parroted three question-distinctive tokens (correcter,
steer, reply) into its claim while citing a glossary article whose
33.5K-char content contains ZERO occurrences of any of them.
Generic linguistic vocabulary (language, communication, terms,
relationships) carried Rule 5's citation-coverage check on its
own; the actual subject tokens rode along unverified.

New per-claim check `_parroted_subject_tokens_absent`: for each
resolving claim, compute the question∩claim content-token set,
then check substring presence in the union of cited evidence
spans (lower-cased, mirroring Rule 5). When ≥ threshold parroted
tokens are absent, emit `SUBJECT_TOKENS_ABSENT` and demote STRICT
→ HYBRID. Default threshold = 3 — single-token absence is often
stem-variant noise; three+ is the parrot fingerprint.

Plumbing:
- New default `DEFAULT_SUBJECT_TOKENS_ABSENT_THRESHOLD = 3`
- Both `verify_claim_lattice` and `verify_claim_lattice_json`
  gain `subject_tokens_absent_threshold` kwarg + per-claim check
  block (mirrors TITLE_MISMATCH plumbing, sits right after it
  in the rule order)
- `claim_lattice_subject_tokens_absent_threshold` policy field
  added to `DEFAULT_QUERY_POLICY` and `DEFAULT_POLICY`; folds
  into `governance_policy_hash` and (via _VERIFIER_POLICY_FIELDS)
  `verifier_policy_hash`
- All four runner/query call sites pass the policy-derived value

Live verification (cache-split cleanly via policy-hash bump):
  pre-fix cache_key 08dbd2c1… : STRICT (false positive)
  post-fix cache_key 6a519636… : UNGROUNDED

Three new unit tests in `tests/test_verify_json.py`:
- threshold-meeting parrot demotes STRICT → HYBRID
- no-op when question is None
- below-threshold absence stays STRICT

Full suite: 776 passed, 34 skipped.
This commit is contained in:
russell@unturf.com 2026-05-02 15:51:58 -04:00
parent d3ad520529
commit 39bebe3fdb
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6 changed files with 311 additions and 13 deletions

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@ -394,3 +394,132 @@ def test_runner_ask_json_mode_passes_guided_json_extra_body(tmp_path):
assert "guided_json" in kwargs["extra_body"]
finally:
conn.close()
# ---------------------------------------------------------------- Rule 9
# Subject-tokens-absent / premise-parroting check (Ticket #000006 amend
# 2026-05-02b). Surfaced by the 200-cycle bench-emergent finding on
# `steer/reply/correcter`: claim affirmed three question-distinctive
# tokens that appeared zero times in the cited 33.5K-char glossary,
# while generic linguistic vocabulary carried Rule 5's coverage check.
def test_verify_json_subject_tokens_absent_demotes_strict_to_hybrid():
"""Reproduces the steer/reply/correcter false-positive shape:
the claim parrots the question's distinctive subject tokens
(correcter, steer, reply) but the cited evidence contains only
generic linguistic vocabulary (language, communication, terms).
Rule 5 passes on the generic overlap; Rule 9 catches that the
question-distinctive tokens are absent and demotes."""
cited_span = (
"Sociolinguistics is the study of language in society and how "
"social factors influence communication. The exchange of meaning "
"between speakers depends on shared terms and discourse "
"relationships. Different aspects of language interact with "
"communication norms in any given community."
)
evidence = [
_ev(
"Eparrot01",
cited_span,
pointer_id="E1",
title="Glossary of language teaching terms and ideas",
),
]
answer = json.dumps({
"claims": [
{
# Three question-distinctive tokens (correcter, steer,
# reply) parroted from question into claim — but ZERO
# of these tokens appear in cited_span.
"text": (
"A correcter can be used to steer a reply by "
"identifying errors in language and communication "
"between speakers, which involves the exchange of "
"meaning across discourse relationships."
),
"evidence_ids": ["E1"],
}
]
})
question = (
"How might a correcter be used to steer a reply in a "
"conversation, and what aspects of language or communication "
"do these terms encompass?"
)
v = verify_claim_lattice_json(answer, evidence, question=question)
assert v["audit_mode"] == "HYBRID", (
f"expected HYBRID via SUBJECT_TOKENS_ABSENT demote; got "
f"{v['audit_mode']} with violations "
f"{[vio['kind'] for vio in v['violations']]}"
)
assert any(vio["kind"] == "SUBJECT_TOKENS_ABSENT" for vio in v["violations"])
# The parroted-but-absent tokens should be reported.
sta = next(vio for vio in v["violations"] if vio["kind"] == "SUBJECT_TOKENS_ABSENT")
absent = set(sta["absent_tokens"])
assert {"correcter", "steer", "reply"}.issubset(absent), (
f"expected correcter/steer/reply in absent_tokens; got {absent}"
)
def test_verify_json_subject_tokens_absent_no_question_skips_check():
"""No question text → Rule 9 is a no-op. STRICT stays STRICT
when every other check passes. Pins that the check requires
question text to operate."""
evidence = [
_ev(
"Enoq00001",
"Brachiosaurus appears in the Jurassic Park film as a herbivore.",
pointer_id="E1",
title="Jurassic Park (film)",
),
]
answer = json.dumps({
"claims": [
{"text": "Brachiosaurus appears in the film", "evidence_ids": ["E1"]},
]
})
v = verify_claim_lattice_json(answer, evidence, question=None)
assert v["audit_mode"] == "STRICT"
assert not any(vio["kind"] == "SUBJECT_TOKENS_ABSENT" for vio in v["violations"])
def test_verify_json_subject_tokens_absent_below_threshold_passes():
"""One absent parroted token → below default threshold of 3 →
no demote. Pins the threshold semantics: single-token absence
is acceptable noise, three+ is the parrot fingerprint."""
cited_span = (
"Brachiosaurus appears in the Jurassic Park film as a herbivore. "
"The dinosaurs in the film were rendered with practical effects "
"and CGI by Industrial Light and Magic."
)
evidence = [
_ev(
"Eonebelow",
cited_span,
pointer_id="E1",
title="Jurassic Park (film)",
),
]
# Question token "extinction" doesn't appear in cited; "brachiosaurus"
# and "film" do. Only 1 parroted-token absent → below threshold 3.
answer = json.dumps({
"claims": [
{
"text": (
"Brachiosaurus appears in the film alongside other "
"dinosaurs after a long extinction"
),
"evidence_ids": ["E1"],
}
]
})
question = (
"How does Brachiosaurus appear in the Jurassic Park film "
"after extinction?"
)
v = verify_claim_lattice_json(answer, evidence, question=question)
assert v["audit_mode"] == "STRICT", (
f"expected STRICT (below threshold); got {v['audit_mode']} "
f"with violations {[vio['kind'] for vio in v['violations']]}"
)