---
conjecture: r2-edh-b1-19
family: codex
model: "gpt-5.6-sol (codex-cli 0.144.0-alpha.4, ChatGPT-subscription auth)"
model_stamp_corrected: "2026-08-07 — archives were first written stamped gpt-5.5 by a runner bug (the stamper read config.toml's default instead of the -m flag actually passed). The calls themselves ran on gpt-5.6-sol throughout; only the label was wrong. Corrected in place, noted here rather than silently."
received: 2026-08-07
template: PROMPT_TEMPLATE_v1.md sha256 4344aabfacfe88362c56d89b6c89d594a7bf3a221e18a16b0e351482447e512f
rivals_parsed: 3
validation: VALID
---

{
  "rivals": [
    {
      "mechanism": "EDH's encoding workflow may suppress the numerator: editors can leave highly ambiguous monument types blank or generic, while assigning controlled types without an uncertainty flag when standardization requires a single value. The measured rate would then reflect database-entry conventions rather than a province-level ceiling.",
      "why_it_explains_the_same_evidence": "A common editorial schema applied across the entire fixed catalogue would keep flagged uncertainty low in both alphabetical halves. Because the denominator includes only monument-typed rows, diverting the most ambiguous cases to blank or generic fields would reproduce both the 18.06% training maximum and the 13.57% holdout maximum without any intrinsic provincial limit.",
      "named_confounds": [
        "missing-not-at-random monument-type fields",
        "controlled-vocabulary standardization",
        "editor or import-batch flagging practices",
        "conditioning the denominator on having a monument type"
      ],
      "discriminating_test": {
        "description": "Blindly re-audit stratified samples of monument-typed and untyped EDH records using object descriptions, editorial notes, and images where available. Record whether the monument identification is substantively uncertain regardless of the structured flag, then recompute province rates and compare false-negative rates across editors or import batches.",
        "computable_on_held_data": true,
        "what_result_favors_rival": "The rival is favored if uncertainty language or visual ambiguity is common in unflagged or untyped records, varies systematically by editorial batch, and corrected rates rise substantially or exceed 25% in any eligible province."
      }
    },
    {
      "mechanism": "The apparent ceiling may be an aggregation effect: large numbers of common, easily classified monument classes dilute much higher uncertainty in rarer or poorly preserved classes. Provincial rates then stay low because provinces have broadly similar mixtures of easy and difficult records, not because uncertainty is capped within provinces.",
      "why_it_explains_the_same_evidence": "The same catalogue-wide composition pattern would occur on both sides of an alphabetical province split. Row-weighted provincial averages could remain below 25% even when particular monument classes have much higher uncertainty, and the minimum-support rule further suppresses unstable extremes among small provinces.",
      "named_confounds": [
        "monument-class composition",
        "row-weighted denominator dilution",
        "preservation-composition differences",
        "minimum-support selection"
      ],
      "discriminating_test": {
        "description": "Estimate row-level uncertainty by broad monument class, preservation or completeness indicators, and province. Test whether a model using only class composition predicts held-out provincial rates, then recompute rates after giving every province the same monument-class distribution and inspect class-specific rates.",
        "computable_on_held_data": true,
        "what_result_favors_rival": "The rival is favored if class composition accurately predicts the held-out rates, residual province effects are negligible, difficult classes exceed 25%, and composition-standardized provincial rates no longer show a uniform sub-25% ceiling."
      }
    },
    {
      "mechanism": "Assignment to a real province may select for documentation quality: poorly documented objects can be disproportionately placed in 'Provincia incerta' or omitted from EDH, and the same poor documentation can make monument type uncertain. Real-province records would therefore be a selected, easier-to-identify subset.",
      "why_it_explains_the_same_evidence": "This selection process operates before the alphabetical split and would depress uncertainty in every real province in both training and holdout. Excluding the uncertain-findspot catch-all preserves that selection, so the observed maxima need not reflect an intrinsic property of provincial material.",
      "named_confounds": [
        "selection on assignable provenance",
        "Provincia incerta catch-all allocation",
        "correlated provenance and monument-type uncertainty",
        "catalogue inclusion or publication bias"
      ],
      "discriminating_test": {
        "description": "Link EDH records to independent excavation or museum inventories that include unpublished fragments and objects with uncertain findspots. Apply the same monument-uncertainty rubric blindly, estimate candidate-province membership for uncertain-findspot objects, and recompute province rates with inverse-probability or multiple-assignment weighting.",
        "computable_on_held_data": false,
        "what_result_favors_rival": "The rival is favored if omitted or uncertain-provenance objects have markedly higher monument-type uncertainty than EDH's real-province records and their inclusion pushes one or more adjusted provincial rates above 25%; a genuine material ceiling predicts that fuller provincial samples remain below the threshold."
      }
    }
  ],
  "no_viable_rival": false,
  "notes": ""
}
