Term Definition
Cluster sampling
A sampling procedure where units of the sampling frame that are similar on one or more variables (typically geographic) are organized into larger groups (i.e. clusters), and a sample of groups is selected. The selected groups contain the units to be included in the sample. The sample may include all units in the selected clusters or a sub-sample of units in each selected cluster. The ultimate purpose of this procedure is to reduce interviewer travel costs for in person studies by producing distinct groups of elements where the elements within each group area are geographically close to one another.