When you are designing a quantitative study, you need to consider the potential power you have to detect effects. Any power analysis you run will have four components:
In education,we also often need to consider multiple factors like how the data are structured, like how random assignment occurred (if it's happening at all), or whether kids are nested in classrooms. These factors add additional elements to these equations. In this powerpoint presentation, I go over some of the features of how to calculate a power analysis when you're planning education research.