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Old 01-17-2014, 09:49 AM
Diamond Dave Diamond Dave is offline
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Quote:
Originally Posted by picassov7 View Post
Precision, on the other hand, is repeatability.
No, that's accuracy.

These are pretty basic scientific concepts that anybody who took a high school chemistry lab should have been taught.

Accuracy means a bathroom scale is always going to say 10 lbs. when a 10 lb. dumbbell is placed on it.

Precision means the scale is going to say 10.45, 9.98, 10.23, 9.62 and 10.01 lbs. if you weigh the dumbbell 5 times. These are more precise answers (down to 1/100 of a lb.), but not necessarily very accurate, since the readings are nearly 1/2 lb. off in one case.

If the scale says 10.00 lbs. every time, it's precise and accurate.

If the scale says 15, 5, 16, 12 and 4, it's neither precise nor accurate.
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