KEY FEATURES: Examples for each statistical expression help readers understand complex formulas A chapter on how to use the literature for power analysis walks readers through the process of making good assumptions A chapter on how to write about power analysis offers 7 key points on what needs to be included in a power analysis

# Reasonable Assumptions

### Reasonable Assumptions

At this point in the volume, the general approach to power analysis should be clear. Each type of power analysis (finding power, finding sample size, finding effect size) makes assumptions about part of the puzzle to compute the target assumption. To find power, we assume an effect size and sample size. To find the sample size, we assume a level of power and an effect size. To find (the minimum) effect size, we assume power and a sample size. For all these, we also always assume a level of Type I error and type of test (but usually this is the uncontroversial $\mathit{\alpha }=0.05$ with two tails). In ...

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