{
  "slug": "right-censoring",
  "term": "Right-censoring",
  "aliases": [],
  "definition": "Right-censoring records that a time-to-event exceeds the last observed event-free time without observing the event time itself.",
  "note": "A disk still running when observation ends contributes known survival time, not a zero lifetime and not a confirmed failure. Retirement without a recorded failure may also censor a record. Estimating survival beyond observation requires appropriate censoring assumptions; retirement selected by health can violate them. A missing SMART measurement is instead a missing covariate and can coexist with a recorded failure.",
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "related": [
    "left-truncation",
    "hazard-rate",
    "drive-day"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "nist-censoring",
      "title": "NIST e-Handbook 8.1.3.1: Censoring",
      "url": "https://www.itl.nist.gov/div898/handbook/apr/section1/apr131.htm",
      "accessed": "2026-10-10"
    },
    {
      "id": "hesela-age-audit",
      "title": "Hesela: Missing SMART ages and the limits of drive-age comparisons",
      "url": "https://hesela.com/analyses/backblaze-age-missing-data-audit/",
      "accessed": "2026-10-11"
    }
  ]
}