MDM_samp_cluster2

Clustered Sampling: when a population is sub-divided into groups or clusters and a sample group is selected for more analysis. All groups must be mutually exclusive, and together the clusters must include the entire population. Example: One-step cluster sampling takes two testers of 100 from a population of 1000, by separating the population randomly into 10 groups and then selecting 2 of the 10 groups as a total for testing. This technique makes sure that both samples are equally represented by the characteristics of the population.

Cluster sampling is considered a two-step process if only some of the individuals in the selected samples are chosen (at random) for testing. An area sample is a type of cluster sample. Area sampling is a method used when an area is used for sampling and then subdivided into smaller groups. These groups are chosen by chance and surveyed.

> //Cluster Sampling//. (n.d.). Retrieved October 28, 2009, from http://www.metagora.org/training/encyclopedia/cluster.html
 * //Cluster Sample//. (n.d.). Retrieved October 28, 2009, from http://score.kings.k12.ca.us/lessons/wwwstats/cluster.sample.html