Difference between revisions of "Precise"

Revision as of 09:14, 25 March 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

The number pi is 3.14159265359 correct to 12 significant figures.

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
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.

@@ Line 1: / Line 1: @@
 ==Key Stage 4==
 ===Meaning===
-[[Results]] are [[precise]] if they given to a large number of [[Significant Figures|significant figures]].
+[[Results]] are [[precise]] if the same [[reading]] or [[measurement]] [[repeat]]edly gives a similar value.
 ===About Precision===
-: [[Results]] may be said to be '''precise''' if each [[repeat]]ed [[result]]s is close to the same [[value]].
+: The smaller the [[range]] and [[uncertainty]] the greater the '''precision'''.
-: The smaller the [[uncertainty]] the greater the '''precision'''.
+: '''Precision''' is achieved by [[Control Variable|controlling]] [[variable]]s so that [[reading]]s are stable over a long period of [[time]].
-: '''Precision''' is achieved by:
-:*Using [[Measuring Instrument|instrument]]s with a high [[resolution]].
-:*[[Control Variable|Controlling]] [[variable]]s so that [[reading]]s are stable over a long period of [[time]]. Sometimes [[reading]]s fluctuate so they cannot be recorded to as many [[Significant Figures|significant figures]] as the [[Measuring Instrument|instrument]] shows.
 ===Accuracy vs Precision===
 : The number [[pi]] is 3.14159265359 correct to 12 [[Significant Figures|significant figures]].
-: 3.1 is an [[accurate]] value for [[pi]] but it is not very [[precise]] - Close to the real number, but not many [[Significant Figures|significant figures]].
+{| class="wikitable"
-: 3.2111 is a [[precise]] value for [[pi]] but it is '''inaccurate''' - Not close enough to the real number, but has several [[Significant Figures|significant figures]].
+|+ Experimental Measurements of [[pi]]
+|-
+| style="height:20px; width:100px; text-align:center;" |'''Method'''
+| style="height:20px; width:100px; text-align:center;" |'''Test 1'''
+| style="height:20px; width:100px; text-align:center;" |'''Test 2'''
+| style="height:20px; width:100px; text-align:center;" |'''Test 3'''
+| style="height:20px; width:100px; text-align:center;" |'''Average'''
+| style="height:20px; width:100px; text-align:center;" |'''Range'''
+|-
+| style="height:20px; width:100px; text-align:center;" |Method 1
+| style="height:20px; width:100px; text-align:center;" |3.27
+| style="height:20px; width:100px; text-align:center;" |3.09
+| style="height:20px; width:100px; text-align:center;" |3.01
+| style="height:20px; width:100px; text-align:center;" |3.12
+| style="height:20px; width:100px; text-align:center;" |0.26
+|-
+| style="height:20px; width:100px; text-align:center;" |Method 2
+| style="height:20px; width:100px; text-align:center;" |3.91
+| style="height:20px; width:100px; text-align:center;" |3.88
+| style="height:20px; width:100px; text-align:center;" |3.88
+| style="height:20px; width:100px; text-align:center;" |3.89
+| style="height:20px; width:100px; text-align:center;" |0.03
+|-
+| style="height:20px; width:100px; text-align:center;" |Method 3
+| style="height:20px; width:100px; text-align:center;" |3.57
+| style="height:20px; width:100px; text-align:center;" |2.89
+| style="height:20px; width:100px; text-align:center;" |2.93
+| style="height:20px; width:100px; text-align:center;" |3.13
+| style="height:20px; width:100px; text-align:center;" |0.68
+|-
+| style="height:20px; width:100px; text-align:center;" colspan = "5"|
+Method 1: The most [[accurate]] [[measurement]]s 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]] [[measurement]]s 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 [[Mean Average|average]] is the most [[accurate]] as it is the closes to [[pi]].
+|}