Sample Size Calculations with R

Abstract A basic question that crops up at the planning stage of an experiment is what should be the sample size. Inference based on too small a sample size may not have a stamp of authority of the conclusions drawn. A too large sample means wastage of valuable resources. It is imperative that the researcher involved takes into account all the relevant factors in order to come up with the right sample size. The purpose of this chapter is to explain what goes into a sample size calculation and lay out the relevant R code for getting the number. The goals in this chapter are modest in the sense we just focus on one-sample, two-sample, and multisample problems only, for quantitative variables.