---
title: "Method Validation: Accuracy, Precision, Recovery and Robustness"
description: "A method is not finished when it produces numbers. Validation is the evidence that the numbers are right, repeatable by someone else, unaffected by small changes, and correct on a sample of known cont"
canonical: https://lightmysky.com/learn/science/method-validation-accuracy-precision-recovery-and-robustness-mt_ihmF2fl4OC
source: https://lightmysky.com/learn/science/method-validation-accuracy-precision-recovery-and-robustness-mt_ihmF2fl4OC.md
retrieved: 2026-09-12
---

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# Method Validation: Accuracy, Precision, Recovery and Robustness

A method is not finished when it produces numbers. Validation is the evidence that the numbers are right, repeatable by someone else, unaffected by small changes, and correct on a sample of known content.

Subject: Science · Area: Chemistry · Ages 21 to 22
Page: https://lightmysky.com/learn/science/method-validation-accuracy-precision-recovery-and-robustness-mt_ihmF2fl4OC

## Ready when they can

- Separates accuracy from precision and names the experiment that tests each
- Designs a spike and recovery experiment and states what a recovery outside the accepted range implies
- Distinguishes repeatability from reproducibility and explains why both are reported
- Plans a robustness check by varying one method parameter at a time and reading the effect

## Lesson: Prove the numbers, not just make them

You already know how to run a method and read a number. Validation asks whether the number deserves trust. Accuracy is closeness to the truth, tested on a sample of known content. Precision is repeatability, tested by running repeats and watching the spread.

**Example.** You spike a blank sample with 10 mg and the method finds 7.8 mg. Recovery is 78 per cent, outside the accepted range. The repeats agree closely, so the method is precise but wrong: something systematically eats part of the sample.

Repeatability means the same hands in the same lab agree. Reproducibility means a different lab agrees too. Both are reported because a method that only works for its inventor is not finished.

**Tip.** Check robustness by varying one method parameter at a time, such as temperature or pH, and reading the effect. Small deliberate changes should barely move the result, or everyday wobble will ruin it.

**Recap.** Accuracy needs known samples, precision needs repeats, other labs must agree, and small changes must not matter.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Potentiometry, Ion-Selective Electrodes and Voltammetry](https://lightmysky.com/learn/science/potentiometry-ion-selective-electrodes-and-voltammetry-mt_7sLJXqFfWR)
- [Calibration, the Blank and What Makes a Measurement Trustworthy](https://lightmysky.com/learn/science/calibration-the-blank-and-what-makes-a-measurement-trustworthy-mt_UNkQFonlWJ)

## Opens up

- [Reading a Paper and Its Supporting Information](https://lightmysky.com/learn/science/reading-a-paper-and-its-supporting-information-mt_8t32DdAY44)