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• A good scientific measurement is made with accuracy and precision.

• Accuracy tells us how close

• a particular measurement is to the correct value.

• For instance,

• how close is the reading of a thermometer to the actual temperature?

• Precision is the consistency of repeated measurement.

• In other words, are the results consistent

• each time something is measured?

• The more consistent the results,

• the more precise the measurement.

• It is possible to have a precise measurement that is not accurate.

• It is also possible to have an accurate measurement that is not precise.

• The best measurements are both accurate and precise!

• Let us look more closely at the difference between accuracy and

• precision using an archer and target.

• The archer is accurate when he hits the bull's eye.

• He is precise when he can consistently hit the same spot on the target,

• in this case the bull's eye, over and over again.

• This archer is both accurate (he hits the bull's eye) and

• precise (he is able to hit the same area of the bull's eye repeatedly).

• It is also possible for the archer to be precise, but inaccurate.

• If he misses the bull's eye, he is inaccurate; he has missed the mark.

• But if he can consistently and

• repeatedly hit the target in the same place,

• even if it is not the bull's eye, he is precise.

• On the other hand, the archer may be accurate, but not precise.

• If he strikes the bull's eye or right next to the bull's eye,

• but his arrows are not consistently placed,

• then the archer is accurate, but not precise.

• In this case,

• the arrows would be spread across the bull's eye

• rather than clumped together in a small area.

• If our archer is having a really bad day,

• he might even be inaccurate and imprecise.

• In this case,

• his arrows will strike the target in a random pattern and

• he will not hit the same part of the target time after time.

A good scientific measurement is made with accuracy and precision.

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B1 US precise archer bull accurate measurement eye

# Accuracy and Precision

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羅紹桀 posted on 2015/07/17
Video vocabulary