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	<title>Sphere spectrum - Revision history</title>
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	<updated>2026-04-18T14:59:57Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
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	<entry>
		<id>https://en.formulasearchengine.com/index.php?title=Sphere_spectrum&amp;diff=23559&amp;oldid=prev</id>
		<title>en&gt;TakuyaMurata: stable homotopy group</title>
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		<updated>2013-12-04T16:39:45Z</updated>

		<summary type="html">&lt;p&gt;stable homotopy group&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;&amp;#039;&amp;#039;&amp;#039;Skill&amp;#039;&amp;#039;&amp;#039; in [[forecasting]] (or &amp;#039;&amp;#039;&amp;#039;skill score&amp;#039;&amp;#039;&amp;#039;,&amp;lt;ref&amp;gt;[http://amsglossary.allenpress.com/glossary/search?id=skill1 Glossary of Meteorology, American Meteorological Society]&amp;lt;/ref&amp;gt; &amp;#039;&amp;#039;&amp;#039;forecast skill&amp;#039;&amp;#039;&amp;#039;, &amp;#039;&amp;#039;&amp;#039;prediction skill&amp;#039;&amp;#039;&amp;#039;) is a scaled representation of [[forecast error]] that relates the forecast accuracy of a particular forecast model to some reference model.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
|[[Mean squared error]] (MSE)&lt;br /&gt;
|&amp;lt;math&amp;gt;\ \mathit{MSE} = \frac{\sum_{t=1}^N {E_t^2}}{N} &amp;lt;/math&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
|Forecast skill (SS)&lt;br /&gt;
|&amp;lt;math&amp;gt;\ \mathit{SS} = 1- \frac{\mathit{MSE}_\text{forecast}}{\mathit{MSE}_\text{ref}} &amp;lt;/math&amp;gt;&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
A perfect forecast results in a forecast skill of 1.0, a forecast with similar skill to the reference forecast would have a skill of 0.0, and a forecast which is less skillful than the reference forecast would have negative skill values.&amp;lt;ref name=&amp;quot;Roebber&amp;quot;&amp;gt;{{Citation&lt;br /&gt;
|last       = Roebber &lt;br /&gt;
|first      = Paul J. &lt;br /&gt;
|year       = 1998&lt;br /&gt;
|title      = The Regime Dependence of Degree Day Forecast Technique, Skill, and Value&lt;br /&gt;
|publisher  = Allen Press &lt;br /&gt;
|journal    = American Meteorological Society -- Weather and Forecasting &lt;br /&gt;
|volume     = 13&lt;br /&gt;
|issue      = 3&lt;br /&gt;
|pages      = 783–794&lt;br /&gt;
|url        = http://ams.allenpress.com/perlserv/?request=get-document&amp;amp;doi=10.1175%2F1520-0434(1998)013%3C0783%3ATRDODD%3E2.0.CO%3B2 &lt;br /&gt;
|accessdate = 2009-01-19&lt;br /&gt;
|doi       = 10.1175/1520-0434(1998)013&amp;lt;0783:TRDODD&amp;gt;2.0.CO;2&lt;br /&gt;
|bibcode = 1998WtFor..13..783R }}&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;Murphy&amp;quot;&amp;gt;{{Citation&lt;br /&gt;
|last       = Murphy &lt;br /&gt;
|first      = Allen H. &lt;br /&gt;
|year       = 1988&lt;br /&gt;
|title      = Skill Scores Based on the Mean Square Error and Their Relationships to the Correlation Coefficient&lt;br /&gt;
|publisher  = Allen Press &lt;br /&gt;
|journal    = American Meteorological Society -- Monthly Weather Review &lt;br /&gt;
|volume     = 116&lt;br /&gt;
|issue      = 12&lt;br /&gt;
|pages      = 2417–2424&lt;br /&gt;
|doi        = 10.1175/1520-0493(1988)116&amp;lt;2417:SSBOTM&amp;gt;2.0.CO;2&lt;br /&gt;
|url        = http://ams.allenpress.com/perlserv/?request=get-abstract&amp;amp;doi=10.1175%2F1520-0493(1988)116%3C2417%3ASSBOTM%3E2.0.CO%3B2 &lt;br /&gt;
|accessdate = 2009-01-19&lt;br /&gt;
|bibcode = 1988MWRv..116.2417M }}&amp;lt;/ref&amp;gt; &lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Statistical forecasting]]&lt;br /&gt;
[[Category:Climate and weather statistics]]&lt;br /&gt;
[[Category:Weather forecasting]]&lt;/div&gt;</summary>
		<author><name>en&gt;TakuyaMurata</name></author>
	</entry>
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