Sample Size Caluclation in R… Extended! This is an extension from a post I saw here. When thinking about study designs for a trial that we want to conduct for a client, one of the things that we need to think about is how many patients we would need to recruit to see the effect that we propose to see? We’re going to walk through a couple of scenarios and see how we need can use R to get at the sample size & power question when desgining our studies.