Sampling Methods in Research Design

Sampling is the selection of a subset of the population of interest in a research study. In the vast majority of research endeavors, the participation of an entire population of interest is not possible, so a smaller group is relied upon for data collection. Sampling from the population is often more practical and allows data to be collected faster and at a lower cost than attempting to reach every member of the population. However, because the sample will be used to make inferences about the population, understanding the means by which the data arrived in the database is an important aspect of analyzing and drawing conclusions from that data. This installment continues the ongoing series of methods and statistics editorials in the Journal. This editorial is focused on common ways that data are observed. Several common sampling designs, uses of sampling designs in headache research, and common problems encountered with sampling are described. While the topic of sampling is vast, this serves as a simple introduction to the concepts.