---
license: cc-by-4.0
tags:
  - interpretability
  - jacobian-lens
  - pythia
  - reproducibility
library_name: pytorch
---

# Corpus and context dependence of the Jacobian lens — artifact mirror

Fitted operators, experimental records and the corpus pool for the accompanying paper.

**Licence.** Everything here is **CC BY 4.0**, without qualification — see `LICENSE`. That is
true by construction, not by assertion: this repository contains only artifacts this work
produced. **No third-party corpus text is distributed here.** The corpus pool is rebuilt from its
public sources by `repro/06_build_corpora.sh` and verified against the manifests that ship here;
8 of 11 corpora rebuilt bit-identically when measured. `ATTRIBUTION.md` has the detail.

## Layout

```
results/lenses/e28/       166 operators + sidecars   corpus x N ladder
results/lenses/plad/       53 operators + sidecars   per-layer activation dumps
results/lenses/ladder/     15 operators + sidecars   canonical model ladder (70m ... 2.8b)
results/lenses/misc/        8 operators              smokes and one-offs
results/<17 experiment dirs>                         per-experiment operators and records
results/*.json            190 experimental records
corpora/                    3 provenance manifests (NO corpus text — rebuild it, see ATTRIBUTION.md)
```

Every `.pt` is a corpus-averaged Jacobian `J_l = E_x[dh_final/dh_l]` fitted with the reference
implementation at pin `581d398`, fp32, TF32 off, uncentered.

## Reproducing

Every statistic in the paper recomputes from `results/**.json` alone — no operators, no GPU:

```bash
git clone <code repository>
uv sync && bash repro/01_setup_local.sh
bash repro/04_fetch_results.sh          # pulls results/**.json from here, ~7 MB
bash repro/RUN_ALL.sh --tier T0         # 12 modules
```

`--tier T1` re-scores the stored operators on CPU and needs the `.pt` from this repo
(`bash repro/03_fetch_artifacts.sh --all`). `--tier T2` refits on GPU.

## Provenance

Each results file carries a provenance block: the producing script and its SHA-256, the commit,
the argv, and the SHA-256 of every declared input. `payload_sha256` covers the record **excluding**
the provenance block, so it is stable across reruns that change only environment metadata — rerun
and compare it, and a match means no number moved.

No hostname is recorded. Input hashes are the values at write time; where a record was later
redacted, `payload_sha256_before_redaction` retains the original so both remain verifiable.

No corpus plaintext is distributed — see `ATTRIBUTION.md` for the rebuild.