Klastriproovivõttu

Klastriproovivõttu, also known as cluster sampling, is a statistical sampling method. It is a type of probability sampling where researchers divide a population into smaller groups, known as clusters. These clusters are typically pre-existing, natural groupings within the population. Examples of clusters could include schools, geographical areas, or households.

The process involves randomly selecting a certain number of these clusters. All individuals within the selected clusters are then included in the sample. Alternatively, a sub-sample of individuals from the selected clusters may be chosen, which is known as two-stage cluster sampling.

This method is often employed when it is impractical or too expensive to obtain a complete list of all members of a population for simple random sampling. For instance, surveying a large, geographically dispersed population might be more efficiently conducted using cluster sampling by selecting specific towns or neighborhoods.

While cluster sampling can be more cost-effective and practical, it may also introduce a higher degree of sampling error compared to simple random sampling, especially if the clusters are not representative of the entire population. The effectiveness of cluster sampling depends on the homogeneity within clusters and heterogeneity between clusters.