http://www.explainxkcd.com/wiki/index.php?title=Special:RecentChangesLinked/Category:Statistics&feed=atom&target=Category%3AStatisticsexplain xkcd - Changes related to "Category:Statistics" [en]2014-10-25T17:48:47ZRelated changesMediaWiki 1.19.17http://www.explainxkcd.com/wiki/index.php?title=892:_Null_Hypothesis&diff=77675&oldid=58110892: Null Hypothesis2014-10-23T06:23:08Z<p><span dir="auto"><span class="autocomment">Explanation: </span> you can't disprove an alternative hypothesis</span></p>
<table class='diff diff-contentalign-left'>
<col class='diff-marker' />
<col class='diff-content' />
<col class='diff-marker' />
<col class='diff-content' />
<tr valign='top'>
<td colspan='2' style="background-color: white; color:black;">← Older revision</td>
<td colspan='2' style="background-color: white; color:black;">Revision as of 06:23, 23 October 2014</td>
</tr><tr><td colspan="2" class="diff-lineno">Line 8:</td>
<td colspan="2" class="diff-lineno">Line 8:</td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Explanation==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Explanation==</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="background: #ffa; color:black; font-size: smaller;"><div>This comic is based on a misunderstanding. The {{w|null hypothesis}} is the hypothesis in a statistical analysis that indicates, essentially, the "status quo." For example, the null hypothesis for a study about cell phones and cancer risk might be "Cell phones have no effect on cancer risk." The ''alternative hypothesis,'' by contrast, is the one we want to prove <del class="diffchange diffchange-inline">or disprove </del>- in this case, probably "Cell phones increase cancer risk."</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>This comic is based on a misunderstanding. The {{w|null hypothesis}} is the hypothesis in a statistical analysis that indicates, essentially, the "status quo." For example, the null hypothesis for a study about cell phones and cancer risk might be "Cell phones have no effect on cancer risk." The ''alternative hypothesis,'' by contrast, is the one we want to prove - in this case, probably "Cell phones increase cancer risk."</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>After conducting a study, we can then make a judgment based on our data. There are statistical models for measuring the probability that a certain result occurred by random chance, even though in reality there is no correlation. If this probability is low enough (usually meaning it's below a certain threshold we set when we design the experiment, such as 5% or 1%), we ''reject'' the null hypothesis, in this case saying that cell phones ''do'' increase cancer risk. Otherwise, we ''fail to reject'' the null hypothesis, as we have insufficient evidence to conclusively state that cell phones increase cancer risk. This is how almost all scientific experiments, from high school biology classes to CERN, draw their conclusions.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>After conducting a study, we can then make a judgment based on our data. There are statistical models for measuring the probability that a certain result occurred by random chance, even though in reality there is no correlation. If this probability is low enough (usually meaning it's below a certain threshold we set when we design the experiment, such as 5% or 1%), we ''reject'' the null hypothesis, in this case saying that cell phones ''do'' increase cancer risk. Otherwise, we ''fail to reject'' the null hypothesis, as we have insufficient evidence to conclusively state that cell phones increase cancer risk. This is how almost all scientific experiments, from high school biology classes to CERN, draw their conclusions.</div></td></tr>
</table>NathanLazarus