ABSTRACT
Sample size is one of the many decisions that researchers must make and be able to support with logic. Pilot studies are usually conducted with small sample sizes, such as 10 to 100. As students and new researchers learn to use statistics, they will find that sample size relates to mathematical properties. Sample size is determined by identifying the minimum number of people or units needed to represent that population well and to produce useful results when subjected to statistical analysis. Major factors that influence the quantitative researcher's choice of sample size include the purpose of the study, the population size from which the sample is being drawn, the amount of variability within the population, the risk of selecting a sample, and the amount of precision wanted from the results. Sample size expectations differ depending on the goal of the study. Researchers frequently conduct pilot studies, which are studies designed to obtain preliminary information on how new treatments and measures work.
