Making sense of the p value
Favorites|Homepage
Subscriptions | sitemap
HOME > > Making sense of the p value

Making sense of the p value

[From: ] [author: ] [Date: 12-04-10] [Hit: ]
A low p-value is indeed rare but you need to look at with respect to the status quo or null hypothesis.The test statistic is SO FAR AWAY from the status quo that it is highly unlikely that it simply happened by chance.So the test statistic must indeed be different from the status quo so we need to reject it.The farther away the test statistic is from the mean, the lower the p-value and the greater evidence we have that the test statistic is significantly different from the status quo or null.Hope that clears it up.......
I don't understand why a lower p value is stronger evidence against the null hypothesis. P value is a probability; so, wouldn't a lower p value mean that your statistic was very lucky (rare)?

-
confused -

You are on the right track but on the wrong side of the road...

A low p-value is indeed "rare" but you need to look at with respect to the "status quo" or null hypothesis.

The "test statistic" is SO FAR AWAY from the status quo that it is highly unlikely that it simply happened by chance. So the test statistic must indeed be "different" from the status quo so we need to reject it.

The farther away the test statistic is from the mean, the lower the p-value and the greater evidence we have that the test statistic is significantly different from the status quo or null.

Hope that clears it up.
1
keywords: Making,value,the,sense,of,Making sense of the p value
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .