Trueness

Closeness of the expected measurement value to the reference value — absence of systematic bias.

Also known as: systematic accuracy, unbiasedness

Trueness describes how close the mean of many repeated measurements is to the true (reference) value. It is one half of accuracy; the other half is precision.

A measurement system is true when this bias is negligibly small. A systematic bias points to a calibration offset, wrong zero setup, or a design shift — none of which disappear with more measurements.

See also

Used in

In the Algorithm Lab

Sources

  • DIN ISO 5725-1: Genauigkeit (Richtigkeit und Präzision) von Messverfahren und Messergebnissen — Teil 1
  • VDA Band 5 — Prüfprozesseignung, 3. Auflage
  • AIAG — Measurement Systems Analysis Reference Manual, 4th Edition (MSA-4)