---
conjecture: r2-edh-b1-25
family: grok
model: "Grok 4.5 expert (chat paste-back via orchestrator window)"
received: 2026-08-06
template: PROMPT_TEMPLATE_v1.md sha256 4344aabfacfe88362c56d89b6c89d594a7bf3a221e18a16b0e351482447e512f
rivals_parsed: 2
note: "FINAL response of the stage — 43/43 survivors now have Family B responses. r2's batch test computable via last_update/work_status fields."
---

{
"rivals": [
{
"mechanism": "The share of rows marked 'no image' largely inherits the uneven presence of published photographs in the source corpora that EDH ingested: some provincial series were issued with extensive plates while others appeared with little or no illustration, producing extreme coverage rates that reflect historical publication practice rather than variation in modern photographic resourcing.",
"why_it_explains_the_same_evidence": "These differences in the source literature are already fixed in the EDH catalogue and are not aligned with alphabetical order, so both the training and holdout halves contain provinces with very high and very low 'no image' rates.",
"named_confounds": [
"historical publication practice regarding plates and illustrations",
"selection effects in what visual documentation entered the source corpora",
"harvest artifact from unevenly illustrated editions"
],
"discriminating_test": {
"description": "For a sample of provinces at both extremes, compare EDH 'no image' rates against the proportion of inscriptions that already carried published photographs in the major source corpora used by EDH; also test whether controlling for source-publication illustration density removes the province-level extremes.",
"computable_on_held_data": false,
"what_result_favors_rival": "If 'no image' rates track the illustration density of the source publications more closely than any available proxy for recent photographic effort or collection resources, the result favours inherited publication practice over contemporary curatorial-resourcing variation."
}
},
{
"mechanism": "Different phases and teams of EDH data entry applied inconsistent policies and resources for attaching or flagging images; because material from particular provinces was processed in particular batches, the resulting 'no image' rates show extreme province-level heterogeneity even though overall photographic effort is not the primary driver.",
"why_it_explains_the_same_evidence": "These batch-level differences are baked into the fixed catalogue and cross the alphabetical split, placing both low-coverage and high-coverage provinces in the training half and again in the holdout half.",
"named_confounds": [
"digitization and data-entry batch effects",
"inconsistent image-attachment policy across entry campaigns",
"harvest artifact tied to processing order or team"
],
"discriminating_test": {
"description": "If EDH metadata identify the entry batch, processing date or source-ingestion campaign for each row, recompute 'no image' rates aggregated by batch rather than by province and test whether the extremes are better explained by batch than by province.",
"computable_on_held_data": true,
"what_result_favors_rival": "If 'no image' rates cluster more tightly by entry batch or campaign than by province, and the province-level extremes disappear once batch is controlled for, the result favours batch/policy variation over province-level photographic resourcing."
}
}
],
"no_viable_rival": false,
"notes": ""
}
