NIST’s explanation of measurement bias adds a useful check to concentration arithmetic.

By S7 Sciences Research DeskUpdated September 30, 20262 min read

Featured original sourceS7 adaptation and commentary

Bias and Accuracy

Institutional authors: NIST and SEMATECH

NIST/SEMATECH e-Handbook of Statistical Methods, section 2.1.1.3 · Undated handbook section; accessed September 30, 2026

“difference between the average of measurements”

The article below is an original S7 Sciences summary and analysis. The quoted passage is brief and attributed; the complete original remains with its author and publisher.

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Agreement with what?

NIST describes accuracy as agreement with a target or reference, and bias as the difference between an average measurement and that reference. Several readings can be close together while all sit away from the reference. Repetition alone therefore does not settle accuracy.

An arithmetic example

Consider an abstract concentration calculation: mass divided by volume. If every mass input is 10% above the reference while volume is correct, every calculated concentration is also 10% high. Repeating the division produces consistent answers without correcting the input error. This is S7’s illustrative arithmetic, not experimental data or a preparation recipe.

Read beyond the decimal

When comparing concentration results, ask about the reference, possible shared errors and the measurement method. More decimal places do not establish accuracy. NIST identifies comparisons with standards and laboratories as ways to investigate bias. This page explains interpretation, not certification of any listed product.

Primary and authoritative sources

Read the evidence behind this article.

Bias and AccuracyInstitutional authors: NIST and SEMATECHNIST/SEMATECH e-Handbook of Statistical Methods, section 2.1.1.3

Official method page reviewed; it displays no section publication date. Numerical illustration is S7-authored.