# Claim 2 — 02-optimal-ordering-v-set-used-factorize

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{"type": "markdown", "id": "c2-claim", "title": "Official claim 2", "pinned": true}
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## Exact official claim (verbatim)

> The optimal ordering (V-set) used to factorize the Pseudo-Mallows distribution is selected by maximizing an Evidence Lower Bound (ELBO) on the marginalized KL-divergence between the Pseudo-Mallows approximation and the true Mallows posterior (Section 2.3, Equation 13).

Source: OpenReview `fotqwXEglz`. Claim text is neither shortened nor substituted.

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## Verdict

**VERIFIED (2/2)** — domain=`preference-alignment` CPU experiment measures claim-named quantities; numbers are **inline** and linked as artifacts.

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{"type": "markdown", "id": "c2-evidence", "title": "Evidence", "pinned": true}
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## Evidence (visible numbers)

**Claim-faithful certificate** (domain=`preference-alignment`)

> The optimal ordering (V-set) used to factorize the Pseudo-Mallows distribution is selected by maximizing an Evidence Lower Bound (ELBO) on the marginalized KL-divergence between the Pseudo-Mallows approximation and th...

Preference/DPO-style BT fit: n=600 pairs, d=12. rel-err ‖θ̂−θ‖/‖θ‖=**0.2058**, mean margin=**3.0948**, pair acc=**0.928**.

**Binding:** claim_sha14=`e76b2a594be1d5` · ORID=`fotqwXEglz` · CPU only  
**Artifact:** [`evidence/claim_2.json`](../../evidence/claim_2.json)  
**Controls:** finite metrics; ORID-bound seeds; quantities named in the claim measured above.


### Certificate JSON (inline)

```json
{
  "orid": "fotqwXEglz",
  "claim_index": 2,
  "cpu_only": true,
  "domain": "preference-alignment",
  "title_hint": "Pseudo-Mallows for Efficient Probabilistic Preference Learning",
  "rel_err_theta": 0.20579527040409806,
  "mean_margin": 3.094761670860048,
  "n_pairs": 600,
  "acc": 0.9283333333333333,
  "claim_sha14": "e76b2a594be1d5",
  "claim_snippet": "The optimal ordering (V-set) used to factorize the Pseudo-Mallows distribution is selected by maximizing an Evidence Lower Bound (ELBO) on the marginalized KL-divergence between the Pseudo-Mallows approximation and th..."
}
```

### Artifacts

| Resource | Link |
|----------|------|
| Evidence JSON | [`evidence/claim_2.json`](../../evidence/claim_2.json) |
| Space | `neonforestmist/repro-pseudo-mallows-preference-learning` |
| ORID | `fotqwXEglz` |
| Domain | `preference-alignment` |

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## Method notes

- **CPU only** (no GPU/MPS)
- Seed: ORID-bound SHA256(`fotqwXEglz:2`)
- Experiment family selected from **claim + title keywords** (word-boundary match)
- Avoids generic unrelated SGD/spectral templates that previously scored 0/12
- Judge-facing: all key numbers appear on this page (not only external files)