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Difference between revisions of "Precise"

(About Precision)
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==Key Stage 5==
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===Meaning===
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[[Results]] are [[precise]] if the same [[reading]] or [[measurement]] [[repeat]]edly gives a similar value.
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===About Precision===
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: A single [[reading]] may be more [[precise]] if the [[resolution]] of the [[Measuring Instrument|measuring instrument]] is higher. This is due to the upper and lower bounds of a single number being smaller when the number has a greater [[resolution]]. A [[ruler]] that [[measure]]s to the nearest 1cm has an [[uncertainty]] of ±5mm for each [[reading]]. A [[ruler]] that [[measure]]s to the nearest 1mm has an [[uncertainty]] of ±0.5mm, making a single [[reading]] more [[precise]].

Revision as of 17:04, 20 April 2019

Key Stage 4

Meaning

Results are precise if the same reading or measurement repeatedly gives a similar value.

About Precision

The smaller the range and uncertainty the greater the precision.
Precision is achieved by controlling variables so that readings are stable over a long period of time.

Accuracy vs Precision

Experimental Measurements of pi
Method Test 1 Test 2 Test 3 Average Range
Method 1 3.27 3.09 3.01 3.12 0.26
Method 2 3.91 3.88 3.88 3.89 0.03
Method 3 3.57 2.89 2.93 3.13 0.68
The number pi is 3.14159265359 correct to 12 significant figures.

Method 1: The most accurate measurements because they are the closest to pi but they are not very precise because they have a range of 0.26.

Method 2: These are the least accurate measurements because they are the furthest from pi but they are very precise because they have a range of only 0.03.

Method 3: Each measurement is not accurate because they are far from pi, they are also the least precise because they have a range of 0.68. However, the average is the most accurate as it is the closes to pi.

Key Stage 5

Meaning

Results are precise if the same reading or measurement repeatedly gives a similar value.

About Precision

A single reading may be more precise if the resolution of the measuring instrument is higher. This is due to the upper and lower bounds of a single number being smaller when the number has a greater resolution. A ruler that measures to the nearest 1cm has an uncertainty of ±5mm for each reading. A ruler that measures to the nearest 1mm has an uncertainty of ±0.5mm, making a single reading more precise.