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Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Omar Sobh
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1537a9464a |
bench: sweep the hybrid weights, and correct the recommendation
CI / test (push) Failing after 3s
Tier 4b reported hybrid retrieval at 0.7/0.3 and noted the weights were "the
documented default, not a searched optimum". `--sweep` searches them: 0.0 to 1.0
in 0.1 steps, reusing the one-time embedding table so eleven configurations cost
barely more than three.
The result is not a refinement. 0.7/0.3 is **strictly dominated**:
vector/keyword Hit@1 Hit@5 Hit@10 MRR sHit@5
0.0 / 1.0 53.8% 75.0% 81.6% 0.6320 93.6%
0.3 / 0.7 53.2% 78.8% 87.2% 0.6463 96.0%
0.4 / 0.6 51.6% 81.4% 87.8% 0.6429 96.8%
0.5 / 0.5 48.2% 81.4% 88.2% 0.6234 97.4%
0.7 / 0.3 44.4% 79.2% 86.0% 0.5868 95.8%
1.0 / 0.0 36.0% 71.8% 81.6% 0.5027 94.2%
0.4/0.6 beats 0.7/0.3 on every metric at both granularities — Hit@1 +7.2pp,
Hit@5 +2.2, Hit@10 +1.8, MRR +0.056. No trade is being made; the default simply
sat on the wrong side of the peak. It is now 0.4/0.6, and README's usage snippet
recommends the same.
This corrects a conclusion I published one commit ago. Measuring only 0.7/0.3, I
wrote that fusion "buys deeper recall and pays for it at rank 1" and advised
callers taking a single top hit to prefer BM25. That was an artifact of the bad
weight, not a property of fusion: at 0.3/0.7 hybrid *beats* BM25 on MRR (0.6463
vs 0.6320) and Hit@5 (78.8% vs 75.0%) while giving up 0.6pp of Hit@1. Both
BENCHMARKS.md and README carry the correction rather than a quiet edit, since
the old text told readers to configure their systems a particular way.
The three-mode ablation rows are kept at their original settings — they measure
the shape of each stage in isolation, and the operating point now comes from the
sweep instead.
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Omar Sobh
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c913cd1cbf |
bench: make the vector stage real, and measure BM25 vs vector vs hybrid (Tier 4b)
CI / test (push) Failing after 2s
Every LongMemEval number this project has published measured BM25 alone. The
bench passed zero-vector embeddings with vector_weight=0.0, so the HNSW/vector
stage — the thing the README credits for retrieval quality — contributed
nothing and was never tested.
An optional `embeddings` feature loads all-MiniLM-L6-v2 via candle and encodes
the corpus for real. It is off by default and nothing in the shipped crates
depends on it, so a project that advertises no heavyweight dependencies keeps
that property; without the feature the bench behaves exactly as before.
Full haystack, n=500, turn-level:
Hit@1 Hit@5 Hit@10 MRR
BM25 only 53.8% 75.0% 81.6% 0.6320
Vector only 36.0% 71.8% 81.6% 0.5027
Hybrid 0.7/0.3 44.4% 79.2% 86.0% 0.5868
Session-level, hybrid leads outright: 88.2 / 95.8 / 97.8 / 0.9158.
The hybrid claim holds for depth and not for precision@1. Hybrid is the best
configuration at Hit@5 and Hit@10 at both granularities — turn-level Hit@5 gains
4.2 points over BM25 and 7.4 over vector-only, which is the result that justifies
running two stages at all. But BM25 alone still leads turn-level Hit@1 and MRR,
so fusing buys deeper recall and pays at rank 1. Callers assembling five memories
of context want hybrid; callers taking a single top hit are better served by BM25
today. The 0.7/0.3 weights are the documented default, not a searched optimum.
omni-cortex's four-signal ablation found the same direction independently — there,
adding BM25 to a dense retriever raised nDCG@5 while lowering Hit@1 and MRR. Two
codebases, two fusion schemes, same trade.
Vector-only trailing BM25 at every turn-level cutoff except Hit@10 is stated
plainly rather than buried: LongMemEval questions share heavy vocabulary with
their evidence turns, which is close to the best case for lexical matching, and
MiniLM at 384-d is a small model.
Implementation notes:
- Texts are deduplicated before encoding. The haystack sessions are drawn from
a shared pool, so 500 questions x 493.5 turns collapses to 190,015 unique
strings — the difference between encoding the corpus once and per question.
- `embeddings-cuda` adds the GPU path, and it is not a convenience: 190k texts
take ~13 min on an RTX 5060 Ti, while the same work on 8 CPU cores was still
unfinished after 30 minutes. The device is selected at runtime with a CPU
fallback, so a machine without CUDA still works.
- Mean-pooling is masked and the output L2-normalised, which is the published
recipe for this checkpoint (not the [CLS] pooler).
One measurement wrinkle, recorded rather than smoothed over: on the oracle
variant BM25-only reads 84.2% Hit@5 with real embedding vectors present against
84.4% with zero vectors — one question of 500 changes rank, MRR identical at
0.6597. On the full haystack the two agree exactly. Weight 0.0 evidently does not
make the vector stage bit-for-bit absent from candidate selection on a small
corpus.
Verified on the Linux dev host: 49 groups / 1659 passed / 0 failed, clippy clean
under -D warnings, fmt clean, with and without the feature.
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Omar Sobh
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7d6e269bf3 |
bench: run the full longmemeval_s haystack, and measure the variant (Tier 4a)
CI / test (push) Failing after 2s
The harness only ever ran longmemeval_oracle — evidence sessions only, which is
a substantially easier corpus than the dataset LongMemEval results are normally
quoted on. Worse, the variant was a hardcoded "oracle" string in both the report
header and the JSON summary, so pointing it at longmemeval_s would have produced
full-haystack numbers labelled oracle.
DatasetProfile now measures the corpus instead of asserting it: sessions and
turns per question, and evidence-session density (the mean share of a question's
haystack sessions that are answer sessions). The variant label and the
session-level degeneracy warning are both derived from that density, so a
mislabelled input file cannot produce a mislabelled result. Measured: 100.0%
density on the oracle variant, 4.0% on longmemeval_s.
The full haystack, all 500 questions, 47.7 sessions and 493.5 turns each:
turn-level session-level
Hit@1 53.8% 86.2%
Hit@5 75.0% 93.6%
Hit@10 81.6% 96.6%
MRR 0.6320 0.8948
Turn-level drops 84.4% -> 75.0% against the oracle variant. That 9.4-point gap
is the price of the real haystack and is exactly why oracle-only numbers should
not be presented as LongMemEval results.
Session-level is now reportable. It was retracted before because at 100% evidence
density every returned document is a hit by construction; at 4.0% density a hit
reflects discrimination, so 93.6% is a real measurement rather than a restatement
of the corpus shape. Per-type it also finally separates: single-session-assistant
100.0% Hit@1 against single-session-preference 33.3% — BM25 has nothing to grip
on a preference question whose evidence shares no vocabulary with the query.
The MemX comparison stays withdrawn. Running the full haystack closes the corpus
half of that mismatch but not the granularity half: MemX measures fact-level over
220,349 records, and this harness measures turn- and session-level.
Two smaller fixes found while running it:
- --limit samples evenly across the file rather than taking a prefix. The
dataset is ordered by question type, so `--limit 20` returned 20
single-session-user questions and nothing else while reading like a
whole-dataset result.
- abstention_accuracy emits null rather than 0.0 when a corpus poses no
abstention questions. longmemeval_s has none, and 0.0000 reads as total
failure at a task that was never asked.
README.md and BENCHMARKS.md now lead with the full-haystack numbers and keep the
oracle figures alongside, labelled as the easier corpus.
Verified on the Linux dev host: 49 groups / 1659 passed / 0 failed, clippy clean
under -D warnings, fmt clean. The full 500-question run takes ~70 s.
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Omar Sobh
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6f5940d042 |
docs: retract degenerate LongMemEval session-level numbers and the MemX comparison
CI / test (push) Failing after 4s
A methodology audit found that two benchmark claims published in this repo two days ago measure the wrong thing. Both are retracted in place rather than quietly edited, with the reasoning recorded. 1. Session-level LongMemEval recall (100.0% Hit@1/5/10, MRR 1.0000, uniform across all six question types) is a degenerate artifact. On the longmemeval_oracle variant the ingested haystack for a question is essentially only that question's evidence sessions, so every returned document belongs to an answer session and session-level hit rate is ~1.0 at rank 0 by construction. The uniform 100% across every question type was the tell. It measured the shape of the corpus, not the retriever. Only the turn-level figure (84.4% Hit@5) carries signal, and it is now the only retrieval number cited. 2. The "clawhdf5 outperforms MemX at turn-level retrieval (84.4% vs 51.6%)" claim was not like-for-like on two independent axes. Confirmed against arxiv:2603.16171: MemX's Hit@5=51.6% / MRR=0.380 is *fact-level* granularity over 220,349 fact-level records drawn from 19,195 sessions, and the paper explicitly notes fact-level "doubl[es] session-level performance". Ours is turn-level on the oracle subset — different granularity, and a corpus smaller by orders of magnitude. A higher number on an easier corpus at a different granularity is not an outperformance claim. Also caveats the vector-search "vs MemX" latency ratios, which compare a single clawhdf5 component (raw vector search) against MemX's end-to-end pipeline figure (embeddings + FTS5 + four-factor re-ranking). The numbers are real; the "speedup" framing overstated by an unquantified margin and is now labelled an order-of-magnitude indication. Adds an explicit scoring-target declaration to BENCHMARKS.md per arXiv 2605.24060, which found that changing scoring target alone alters nDCG on 83-94% of queries and can reverse system rankings. States dataset variant, metric (retrieval recall, NOT the official QA-accuracy metric), granularity, k, and that the vector stage is inert (zero embeddings, vector_weight=0.0). The harness itself now prints its scoring target, flags the session-level block as degenerate, warns against the MemX comparison, and emits dataset_variant/scoring_target/k/session_level_degenerate in its JSON summary, so the caveats travel with the numbers instead of living only in docs. |
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redclawsystems
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3f222f6956 | Merge pull request 'docs(clawhdf5): document DType variants, fix unresolved doc links' (#17) from sdlc-docs/clawhdf5-types-20260514-165210 into main |