{"abstract":"disagreeing annotations are collapsed to a winner.","category":"Preference pair construction","checks":6,"contract":"Rows are [chosen,rejected] votes for one pair. Return that orientation only if every vote agrees; empty or conflicting votes return None.","contract_signature":"votes","evaluation_group":"preference-annotator-agreement","failed_approach":"Using a floor-half agreement threshold still accepts a two-vote split as decisive.","family":"w3-preference-pair-construction-annotator-agreement","id":"FA-100121","implementations":{"attempt":{"sha256":"d44f4943f4fa4fda6bf61801185834b278c27c8336da3cdf966b95de95e673a6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(votes):\n    return votes[0] if votes and votes.count(votes[0])>=len(votes)//2 else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\na='a'+str(N); b='b'+str(N)\ncheck('unanimous',solve([[a,b],[a,b],[a,b]]),[a,b])\ncheck('split vote',solve([[a,b],[b,a]]),None)\ncheck('minority reversal',solve([[a,b],[a,b],[b,a]]),None)\ncheck('empty',solve([]),None)\ncheck('single vote',solve([[a,b]]),[a,b])\ncheck('reverse unanimous',solve([[b,a],[b,a]]),[b,a])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"25118df9b5e3a1f87d87c0419b950044d3082b71359db98c2344fd6e3bd3da46","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(votes):\n    return votes[0] if votes else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\na='a'+str(N); b='b'+str(N)\ncheck('unanimous',solve([[a,b],[a,b],[a,b]]),[a,b])\ncheck('split vote',solve([[a,b],[b,a]]),None)\ncheck('minority reversal',solve([[a,b],[a,b],[b,a]]),None)\ncheck('empty',solve([]),None)\ncheck('single vote',solve([[a,b]]),[a,b])\ncheck('reverse unanimous',solve([[b,a],[b,a]]),[b,a])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"These are explicit toy record contracts; they do not claim compatibility with a trainer or improved model behavior. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w3-preference-pair-construction-annotator-agreement","generated_at":"2026-09-30T16:48:32.170436+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A small deterministic preference-data transform makes pair semantics inspectable without a training framework.","root_cause":"The constructor trusts the first vote and ignores contradictory annotations that follow.","sha256":"0157a8238ada2c0b4880972f5fa1919ad19cdc14b5de6fd77ecec9792a139b62","title":"Preference pairs: disagreeing annotations are collapsed to a winner · case 01","variant":1,"variant_policy":"The fixture code references N, supplied as 1 through 5. Fixed boundary checks may repeat. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":30.289,"exit_code":1,"observations":[{"actual":["a1","b1"],"check":"unanimous","expected":["a1","b1"],"passed":true},{"actual":["a1","b1"],"check":"split vote","expected":null,"passed":false},{"actual":["a1","b1"],"check":"minority reversal","expected":null,"passed":false},{"actual":null,"check":"empty","expected":null,"passed":true},{"actual":["a1","b1"],"check":"single vote","expected":["a1","b1"],"passed":true},{"actual":["b1","a1"],"check":"reverse unanimous","expected":["b1","a1"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"unanimous\", \"actual\": [\"a1\", \"b1\"], \"expected\": [\"a1\", \"b1\"], \"passed\": true}, {\"check\": \"split vote\", \"actual\": [\"a1\", \"b1\"], \"expected\": null, \"passed\": false}, {\"check\": \"minority reversal\", \"actual\": [\"a1\", \"b1\"], \"expected\": null, \"passed\": false}, {\"check\": \"empty\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"single vote\", \"actual\": [\"a1\", \"b1\"], \"expected\": [\"a1\", \"b1\"], \"passed\": true}, {\"check\": \"reverse unanimous\", \"actual\": [\"b1\", \"a1\"], \"expected\": [\"b1\", \"a1\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":30.228,"exit_code":1,"observations":[{"actual":["a1","b1"],"check":"unanimous","expected":["a1","b1"],"passed":true},{"actual":["a1","b1"],"check":"split vote","expected":null,"passed":false},{"actual":["a1","b1"],"check":"minority reversal","expected":null,"passed":false},{"actual":null,"check":"empty","expected":null,"passed":true},{"actual":["a1","b1"],"check":"single vote","expected":["a1","b1"],"passed":true},{"actual":["b1","a1"],"check":"reverse unanimous","expected":["b1","a1"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"unanimous\", \"actual\": [\"a1\", \"b1\"], \"expected\": [\"a1\", \"b1\"], \"passed\": true}, {\"check\": \"split vote\", \"actual\": [\"a1\", \"b1\"], \"expected\": null, \"passed\": false}, {\"check\": \"minority reversal\", \"actual\": [\"a1\", \"b1\"], \"expected\": null, \"passed\": false}, {\"check\": \"empty\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"single vote\", \"actual\": [\"a1\", \"b1\"], \"expected\": [\"a1\", \"b1\"], \"passed\": true}, {\"check\": \"reverse unanimous\", \"actual\": [\"b1\", \"a1\"], \"expected\": [\"b1\", \"a1\"], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}