Two-stage area sampling
Two-stage area sampling is a method used in statistical research to gather data from a large geographical area by dividing it into smaller, more manageable units. This method is commonly used in surveys and studies where it is not feasible to collect data from every individual in the population.
The first stage of two-stage area sampling involves dividing the population into smaller areas or clusters. These clusters are then randomly selected to be included in the study. In the second stage, a sample is taken from within each selected cluster to gather data from individuals or households.
For example, suppose a researcher wants to conduct a survey on household income in a city. They may first divide the city into neighborhoods or blocks. Then, they randomly select a certain number of neighborhoods to include in the study. Finally, within each selected neighborhood, a sample of households is chosen to provide data on income levels.
Two-stage area sampling is a useful tool for researchers as it allows them to collect data from a large population while keeping costs and resources manageable. It also helps to ensure that the sample is representative of the entire population, as clusters are randomly selected.
Example of two-stage area sampling:
- Divide a city into neighborhoods
- Randomly select neighborhoods to include in the study
- Take a sample of households within each selected neighborhood
For more information on two-stage area sampling, you can visit Wikipedia.