For grant proposals the investigator has to include an estimation of sample size.The size of the sample should be adequate enough so that there is sufficient data crewman talc to reliably answer the research question being addressed by the study.At the very planning stage of the study the investigator has to involve the statistician.To have meaningful dialogue with the statistician every research worker should be familiar with the basic concepts of statistics.
This paper is marc bolan grab concerned with simple principles of sample size calculation.Concepts are explained based on logic rather than rigorous mathematical calculations to help him assimilate the fundamentals.