{
  "version": 1,
  "grade_source": "User-provided Canvas gradebook excerpt, 21 September 2026",
  "oj_extracted_at": "2026-09-21T07:08:23+00:00",
  "homework_window_end": "2026-09-15T23:59:00+08:00",
  "exam_started_at": "2026-09-16T12:00:00+08:00",
  "pre_exam_verified": true,
  "eligible_roster": 41,
  "excluded_test_accounts": 1,
  "available_grades": 26,
  "matched": 26,
  "grades_not_in_excerpt": 15,
  "window_submitters": 39,
  "window_submissions": 2101,
  "matched_submissions": 1507,
  "homework_discrepancies": 2,
  "mean": 90.02,
  "median": 93.25,
  "distribution": [
    {
      "label": "Below 80",
      "n": 5
    },
    {
      "label": "80–<90",
      "n": 5
    },
    {
      "label": "90–<100",
      "n": 10
    },
    {
      "label": "100 or above",
      "n": 6
    }
  ],
  "associations": [
    {
      "metric": "attempts",
      "label": "Submission count",
      "n": 26,
      "rho": 0.3515,
      "bootstrap_interval": [
        -0.0691,
        0.6948
      ],
      "valid_bootstrap_draws": 5000,
      "leave_one_out_range": [
        0.2704,
        0.4568
      ],
      "complete_problem_coverage": {
        "n": 23,
        "rho": 0.2548
      },
      "without_homework_discrepancies": {
        "n": 24,
        "rho": 0.2587
      }
    },
    {
      "metric": "first_score",
      "label": "Mean first-submission score",
      "n": 26,
      "rho": -0.2498,
      "bootstrap_interval": [
        -0.6034,
        0.137
      ],
      "valid_bootstrap_draws": 5000,
      "leave_one_out_range": [
        -0.3438,
        -0.1851
      ],
      "complete_problem_coverage": {
        "n": 23,
        "rho": -0.2873
      },
      "without_homework_discrepancies": {
        "n": 24,
        "rho": -0.2472
      }
    },
    {
      "metric": "late_pct",
      "label": "Share submitted in final 24 hours",
      "n": 26,
      "rho": -0.4774,
      "bootstrap_interval": [
        -0.7848,
        -0.0684
      ],
      "valid_bootstrap_draws": 5000,
      "leave_one_out_range": [
        -0.6045,
        -0.4246
      ],
      "complete_problem_coverage": {
        "n": 23,
        "rho": -0.4299
      },
      "without_homework_discrepancies": {
        "n": 24,
        "rho": -0.4741
      }
    }
  ],
  "attempt_groups": [
    {
      "label": "Under 35",
      "n": 9,
      "mean": 81.0,
      "q1": 69.5,
      "median": 84.5,
      "q3": 92.5
    },
    {
      "label": "35–59",
      "n": 11,
      "mean": 95.27,
      "q1": 89.0,
      "median": 94.5,
      "q3": 102.5
    },
    {
      "label": "60 or more",
      "n": 6,
      "mean": 93.92,
      "q1": 92.25,
      "median": 96.25,
      "q3": 98.38
    }
  ],
  "bootstrap": {
    "draws": 5000,
    "seed": 20260921,
    "unit": "student",
    "method": "paired percentile 95%"
  },
  "privacy": "Aggregate-only; group n >= 5; no identifiers, individual marks, minima or maxima. Not a formal privacy guarantee.",
  "input_sha256": {
    "oj_metrics.tsv": "508918130c0b871c9d7ae7f232cafa00c8eab4e75ed04308f603af9d6f115886",
    "canvas_midterm.csv": "0b9ef3cc836dd1e7aa90861259916afbcc949ff0badfbf7ff73f4e4b51edbf63",
    "provenance.json": "c0a7ee4f9122f0423651b42b8bd4f45ba59b723455c2ca28f3253e053d631d65"
  }
}