Difference between Accuracy and Repeatability | Accuracy vs Repeatability

This page compares Accuracy vs Repeatability and mentions difference between Accuracy and Repeatability.

Accuracy

Definition:
The accuracy of instrument is a measure of how close output reading is to the correct value. Measurements which are close to each other are said to be precise.

Repeatability

Definition:
It describes closeness of output readings when the same input is applied repetitively over a short period of time and multiple repetitive tests are conducted. All the tests provide same or closer results.

Repetitive measurements require following parameters to be kept same in all the tests.
• instrument
• location
• observer
• measurement conditions
• conditions of use

Example:
A game in which small pointed missiles called darts are thrown at a dartboard with middle circle as the target. This is shown in the figure and following results are derived to understand difference between accuracy and repeatability.
➨Result (A): Not accurate, Not repeatable
➨Result (B): Not accurate, But repeatable
➨Result (C): Accurate and Repeatable both

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