What’s the difference between accuracy and precision?

Question

What’s the difference between accuracy and precision?

In: Other

Answer 1

Accuracy is how close your measurement is to a known value. Precision is how close repeated answers are.

Say a container of rice is known to have about 10000 grains, and you decide to count them, making two separate counts to gauge precision. The results of the two counts will determine how accurate and precise you are, as listed below:

10500 first count, 9500 second count – Accurate, but not precise.
5500 both counts – Precise, but not accurate.
10000 both counts – Both accurate and precise.