what is the difference between accuracy and precision?

Answer 1

Precision is the cloeseness of a set of measured values to each other.

Accuracy is a measure of how close the values are to the actual value.

Imagine a bullseye. You throw darts, and they all land in the lower left part of the outermost circle. You are precise, but not very accurate. Now, if you rethrew them, and they all landed in the bullseye, then you would be accurate as well.

Answer 2

Accuracy: The ability of a measurement to match the actual value of the quantity being measured

Precision: The ability of a measurement to be consistently reproduced.

You can be consistently precise but not totaling 100%. Being accurate is the state of being 100% in total value. A Precise measurement could equal 99.9%.

Answer 3

I would say accuracy is more like being close, but not 100%, where as precision is spot-on.

More specifically, accurate is deviating only slightly or within acceptable limits from a standard and precision is state or quality of being exact.

Answer 4

Precision is the ability to get the same result time after time after time, even if the result is wrong.

Accuracy is a measure of ability or consistancy for getting the correct result.

Answer 5

precision just means that you're hitting the same mark every time, the results are always the same. Accuracy however means how true the results are. for example, if you keep hitting the same spot on a dart board that's presicion, if you hit the bulls eye eight times out of ten that's accuracy

Answer 6

Weird but cool question...

I think accuracy is to be exact. Precision is the effort you put in what you do (say or whatever) in order to be accurate.

Answer 7

Precision is when you get the same results that are simlair, accuracy is when you get at least one that is correct

Answer 8

Both of these have to do with repeated measurements.

Accuracy = being close to the right answer
Precision = being close to your other answers
So you want to be both accurate and precise.

Here's a good diagram of the differences:
http://www.who.int/hac/techguidance/tools/disrupted_sectors/accuracy_precision.gif

Diagram B is accurate because the arrows all average to the bullseye (even though each individual arrow is pretty far).
Diagram C is precise because all the arrows hit close to each other (but they're not close to the bullseye).
Diagram A is both, because they're close to the bullseye and close to each other.
Diagram D is neither.

Answer 9

accuracy is to get close to the measurement precision is to be exactly there

Answer 10

Let's make it an analogy using arrows and a target. Your center is what you are aiming for. If you hit that mark - you are accurate. If you consistently miss the mark but keep hitting the same spot somewhere else - you are precise.