{
  "dataset": "cranfield",
  "index": "cranfield-v0",
  "run": "live-opensearch",
  "generatedAt": "2026-07-04T00:00:00.000Z",
  "k": 10,
  "queryCount": 225,
  "metrics": {
    "map": 0.2402,
    "ndcgAt10": 0.2995,
    "precisionAt10": 0.2316,
    "recallAt10": 0.3994,
    "mrr": 0.535
  },
  "notes": [
    "This is a transparent BM25 baseline, not a tuned retail ranking model.",
    "Correct means the returned document appears in the Cranfield qrels with a positive relevance grade.",
    "Wrong or missed examples are useful: they show where lexical BM25 matches words but misses the human relevance judgment."
  ],
  "examples": [
    {
      "type": "strong",
      "label": "Strong baseline case",
      "queryId": "3",
      "query": "what problems of heat conduction in composite slabs have been solved so far .",
      "relevantCount": 8,
      "metrics": {
        "precisionAt10": 0.6,
        "recallAt10": 0.75,
        "ndcgAt10": 0.7892,
        "reciprocalRank": 1
      },
      "correctResults": [
        {
          "rank": 1,
          "id": "399",
          "grade": 3,
          "title": "conduction of heat in composite slabs ."
        },
        {
          "rank": 2,
          "id": "144",
          "grade": 3,
          "title": "heat flow in composite slabs ."
        },
        {
          "rank": 4,
          "id": "5",
          "grade": 3,
          "title": "one-dimensional transient heat conduction into a double-layer slab subjected to a linear heat input for a small time internal ."
        }
      ],
      "wrongOrWeakResults": [
        {
          "rank": 3,
          "id": "485",
          "grade": -1,
          "title": "linear heat flow in a composite slab .",
          "reason": "Looks lexically close, but the Cranfield judgment marks it non-relevant for this query."
        }
      ],
      "missedRelevant": [
        {
          "id": "6",
          "grade": 3
        },
        {
          "id": "119",
          "grade": 3
        }
      ]
    },
    {
      "type": "mixed",
      "label": "Mixed case",
      "queryId": "1",
      "query": "what similarity laws must be obeyed when constructing aeroelastic models of heated high speed aircraft .",
      "relevantCount": 28,
      "metrics": {
        "precisionAt10": 0.5,
        "recallAt10": 0.1786,
        "ndcgAt10": 0.3489,
        "reciprocalRank": 1
      },
      "correctResults": [
        {
          "rank": 1,
          "id": "51",
          "grade": 3,
          "title": "theory of aircraft structural models subjected to aerodynamic heating and external loads ."
        },
        {
          "rank": 2,
          "id": "13",
          "grade": 4,
          "title": "similarity laws for stressing heated wings ."
        },
        {
          "rank": 4,
          "id": "184",
          "grade": 2,
          "title": "scale models for thermo-aeroelastic research ."
        }
      ],
      "wrongOrWeakResults": [
        {
          "rank": 3,
          "id": "486",
          "grade": -1,
          "title": "similarity laws for aerothermoelastic testing .",
          "reason": "The title looks highly related, but the qrel grade is negative for this query."
        },
        {
          "rank": 6,
          "id": "746",
          "grade": 0,
          "title": "aeroelastic problems in connection with high speed flight .",
          "reason": "Word overlap is strong, but it is not one of the judged relevant documents."
        }
      ],
      "missedRelevant": [
        {
          "id": "14",
          "grade": 4
        },
        {
          "id": "15",
          "grade": 4
        },
        {
          "id": "52",
          "grade": 4
        }
      ]
    },
    {
      "type": "weak",
      "label": "Failure case",
      "queryId": "13",
      "query": "what is the basic mechanism of the transonic aileron buzz .",
      "relevantCount": 4,
      "metrics": {
        "precisionAt10": 0,
        "recallAt10": 0,
        "ndcgAt10": 0,
        "reciprocalRank": 0
      },
      "correctResults": [],
      "wrongOrWeakResults": [
        {
          "rank": 1,
          "id": "496",
          "grade": -1,
          "title": "a theory of transonic aileron buzz, neglecting viscous effects .",
          "reason": "The lexical match is excellent, but Cranfield marks it non-relevant to the requested mechanism."
        },
        {
          "rank": 2,
          "id": "313",
          "grade": 0,
          "title": "on alternative forms for the basic equations of transonic flow theory .",
          "reason": "Matches transonic vocabulary but misses the aileron buzz information need."
        }
      ],
      "missedRelevant": [
        {
          "id": "64",
          "grade": 2
        },
        {
          "id": "65",
          "grade": 4
        },
        {
          "id": "265",
          "grade": 2
        },
        {
          "id": "311",
          "grade": 4
        }
      ]
    }
  ]
}