hcistats:poweranalysis

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hcistats:poweranalysis [2014/03/29 02:19] Koji Yatani [Retrospective Power Analysis (not recommended)] |
hcistats:poweranalysis [2014/03/29 02:20] (current) Koji Yatani [Introduction] |
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=====Introduction===== | =====Introduction===== | ||

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NHST can tell you how likely randomly sampled data would be like your data or even more extreme than it given that the null hypothesis (//e.g.//, there is no difference in the mean across the groups to compare) is true. As a standard threshold, we use 0.05, and we call this //alpha//. This means that if randomly sampled data can be like your data at lower than 5% change, you reject the null hypothesis (and claim that we observe a difference). Thus, if your p value is lower than //alpha//, we say that you have a significant result. | NHST can tell you how likely randomly sampled data would be like your data or even more extreme than it given that the null hypothesis (//e.g.//, there is no difference in the mean across the groups to compare) is true. As a standard threshold, we use 0.05, and we call this //alpha//. This means that if randomly sampled data can be like your data at lower than 5% change, you reject the null hypothesis (and claim that we observe a difference). Thus, if your p value is lower than //alpha//, we say that you have a significant result. | ||

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- | ^^Reject the null hypothesis^Fail to reject the null hypothesis^ | + | ^ ^Reject the null hypothesis^Fail to reject the null hypothesis^ |

|The null hypothesis is true.|**Type I error** (false positive)|True negative| | |The null hypothesis is true.|**Type I error** (false positive)|True negative| | ||

|The null hypothesis is false.|True positive|**Type II error** (false negative)| | |The null hypothesis is false.|True positive|**Type II error** (false negative)| |

hcistats/poweranalysis.txt ยท Last modified: 2014/03/29 02:20 by Koji Yatani