{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://www.calculatorx.com/schemas/engineering.conformity.z_score.input.json",
  "title": "Proficiency-testing z-score — input",
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "ylab": {
      "type": "number",
      "description": "Laboratory / participant result. Aliases: y, x."
    },
    "xref": {
      "type": "number",
      "description": "Assigned or reference value. Aliases: X, ref."
    },
    "sigma": {
      "type": "number",
      "exclusiveMinimum": 0,
      "description": "Standard deviation for proficiency assessment σ_pt (SDPA). Aliases: sigma_pt, sdpa, s_pt. Not laboratory u and not expanded U."
    }
  },
  "required": [
    "ylab",
    "xref",
    "sigma"
  ],
  "description": "ISO 13528 z-score z = (ylab−xref)/σ_pt. σ_pt is the scheme standard deviation for proficiency assessment (SDPA), not laboratory u and not expanded U. |z| ≤ 2 pass, 2 < |z| < 3 warning, |z| ≥ 3 fail. Not zeta, not En, and not an ILAC G8 spec decision. (calculation_version 1.0.0)"
}