Power analysis using the web

Power analysis using the web - Power analysis using...

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Power analysis using “Java applets for power and sample size” ESM 206 Nov. 19 2007 The most useful of the online power analysis tools is at http://www.math.uiowa.edu/~rlenth/Power/ . We will learn how to use this using the one- sample t-test from the first question on the problem set (calcium concentrations). Navigate to the site. Prominently displayed near the upper left of the page (below the cow) is a section titled “Select the analysis to be used in your study.” Java takes a moment to load, and then you will see a list of tests for which you can do a power analysis. Select “One-sample t test” and click “Run selection.” You will see the following: Resize it so that you can see everything on the bottom. On this screen, sigma is the standard deviation of the data, “True |mu - mu_0|” is the effect size, n is the sample size, power is 1- β , and alpha is α . You can adjust the first 4 with the sliders, and the last with the drop-down box. For these data, sigma is 1.787.
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Power analysis using the web - Power analysis using...

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