---
conjecture: r2-edh-b1-04
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 may contain different kinds of inscription assemblages in different provinces: some are dominated by intact, formulaic, or historically anchored texts, while others contain many fragmentary or undiagnostic objects. Physical preservation and assemblage composition, rather than province-specific conventions or cataloguing depth, would then determine whether start dates can be resolved.",
      "why_it_explains_the_same_evidence": "Genre, completeness, and archaeological recovery practices are geographically clustered and can produce provinces containing almost entirely dateable records or overwhelmingly undateable fragments. Because those clusters occur on both sides of an alphabetical split, this mechanism naturally permits the observed low and high extremes in both training and holdout provinces.",
      "named_confounds": [
        "inscription-genre composition",
        "physical preservation and text completeness",
        "archaeological recovery and survival bias"
      ],
      "discriminating_test": {
        "description": "Using EDH fields and transcriptions, model resolved-date status from inscription type, material, text length, lacuna rate, formulaic content, and preservation indicators. Recalculate province shares after standardizing every province to the same covariate distribution, and estimate residual province effects within matched strata.",
        "computable_on_held_data": true,
        "what_result_favors_rival": "The rival is favored if standardized province shares cease to span the registered thresholds and province effects become small within composition-and-preservation strata; the stated mechanism instead predicts substantial residual province heterogeneity after this adjustment."
      }
    },
    {
      "mechanism": "The extremes may arise because EDH incorporated geographically concentrated source corpora with different inclusion rules: a thematic or chronology-oriented corpus may contribute almost only dateable inscriptions, whereas an exhaustive regional inventory contributes many undateable fragments. Province is therefore a proxy for selection into EDH, not the cause of date resolution among the underlying inscriptions.",
      "why_it_explains_the_same_evidence": "If contributing corpora are concentrated by province, their inclusion rules can drive dated shares toward either zero or one. Multiple such corpora distributed across province names would reproduce both tails in the training and alphabetical holdout sets without requiring genuinely province-specific resolution practices.",
      "named_confounds": [
        "selection into the catalogue",
        "source-corpus inclusion criteria",
        "geographic concentration of contributing publications"
      ],
      "discriminating_test": {
        "description": "For each province, compare EDH with an independent, near-exhaustive regional inventory or a probability sample of published and museum-held inscriptions. Measure EDH inclusion separately for dated and undated objects, then calculate dated shares in the external inventory rather than only among EDH records.",
        "computable_on_held_data": false,
        "what_result_favors_rival": "The rival is favored if EDH inclusion is strongly conditional on dateability in opposite directions across provinces and the external inventories show markedly less extreme province shares. Persistence of the extremes in independently ascertained inventories would favor the stated mechanism."
      }
    },
    {
      "mechanism": "Resolved start dates may partly reflect source-specific migration or encoding rules rather than actual dating work: some imported record batches may convert broad chronological labels or defaults into numeric start dates nearly universally, while other batches leave equivalent information null. Geographic concentration of those batches would create province-level extremes.",
      "why_it_explains_the_same_evidence": "A schema-level rule applies to whole batches and can consequently generate dated shares near 100% or very low shares. If different batches cover provinces on both sides of the alphabetical division, the same extreme pattern will recur in training and holdout even though underlying chronological information is not comparably complete.",
      "named_confounds": [
        "source-database migration rules",
        "date-field missing-value conventions",
        "placeholder or coarse-date encoding",
        "geographic clustering of import batches"
      ],
      "discriminating_test": {
        "description": "Group records by bibliographic source or import provenance and examine start-date heaping, interval width, presence of end dates, and repeated default values. Then redefine resolution to require a narrow date interval or explicit dating evidence and recompute province shares, while estimating province effects within source batches.",
        "computable_on_held_data": true,
        "what_result_favors_rival": "The rival is favored if the nominally high-coverage provinces are dominated by coarse or defaulted dates, their shares fall below the high threshold under the stricter definition, and missingness is explained chiefly by source batch rather than province within batches."
      }
    }
  ],
  "no_viable_rival": false,
  "notes": "The replicated extremes establish descriptive generalization across the alphabetical split, but province-level tail values alone do not identify which stage of the record-generating process produced them."
}
