neochart v2 research

assist/r5/POSTMORTEM.md

Source: assist/r5/POSTMORTEM.md

Exact source text

# One-page post-mortem: why embedding retrieval failed

QA1's independent Round 4 held-out review reports **3/75 element/passage
precision (4%) and 0/20 strict gold-span recall**, with only two gold concepts
recovered elsewhere in the opinions. Two cases received no proposals. Exact
variants were deliberately withheld. The failed result is preserved; the next
experiment will not retune R4 using these labels.

**Boilerplate trapping.** An element description resembles its legal test.
Embedding a LAW checklist and retrieving nearby language therefore ranks
statutory recitations and standard-of-review paragraphs highly. Lexical cues
such as “plaintiff,” “evidence,” and “here” also occur in these paragraphs. QA1
reports that most rejections were generic legal standards. Tightening citation
anchors removed cross-law output by construction, but did not establish that
this court applied the element to these parties. Syllabi and counsel sections
can mention the right statute without supplying operative findings.

**Wrong unit of retrieval.** A 55-word segmentation plus overlapping windows
uses text length as a proxy for legal structure. It can split the factual
premise from the court's conclusion or combine one with an unrelated citation.
The model sees similar wording, not a reliably identified court/party/claim/
opinion relationship. Comparator precedent facts are especially dangerous:
they are concrete, semantically relevant and nevertheless about another case.
A target-section gate also misses scope mismatches such as Title VII versus
ADA analysis, §1983 versus §1988 fees, or §841 versus sentencing rules.

**Applied versus announced.** The essential question is relational: what did
THIS court decide about THIS element of THIS law on THESE parties' facts?
A remand announcing a legal framework, a historical conviction, a procedural
ruling and an applied factual finding can all share the same vocabulary. The
frozen procedural filters were crude proxies; they could reject mixed cases
and retain boilerplate. Removing exact variants prevented unsupported transfer
of CASE-specific labels, but did not fix element attribution.

**Recall needs careful interpretation.** Strict containment measures recovery
of QA1's chosen evidence span. It gives zero when an accepted proposal captures
a different passage for the same issue. QA1 explicitly identified that effect
in Sacchi and Bittermann, and reported 2/20 substantive concept recovery.
That nuance does not rescue a system with 72/75 rejected proposals. Neither
shorter excerpts nor faster second-pass review establishes annotator savings;
QA1 read the opinions before adjudicating, with no randomized control.

**The next test.** Give a fresh LLM agent the entire provided canonical IR
opinion and the target law's element checklist. Ask it to distinguish current
application from quoted standards, comparator facts and procedural history;
allow abstention and require a unique contiguous verbatim quote for every
candidate. Mechanically locate exact quotes, reject rather than repair invalid
ones, and retain all outputs as unreviewed. Freeze the prompt/protocol before
20 new cases, meter provider tokens and time per case, and send the unchanged
batch to QA1. This tests whether whole-opinion interpretation improves the
proposal mechanism; it does not assume an LLM's reasoning or quote fidelity
makes its legal labels correct.

Source: `neov2/qa/assist-r4-QA1.md`. No R4 labels or source text changed.