Traditional Culture Encyclopedia - Traditional culture - What are the advantages of hierarchical data extraction technology?
What are the advantages of hierarchical data extraction technology?
Stratified sampling, also known as categorical sampling or type sampling, is a method and process that stratifies the sampling population according to a certain identifier, and then extracts sample units from each layer to form samples for data collection and parameter estimation. .
Stratified sampling is a sampling technique often used in social survey practice. It has the following characteristics.
(1) Stratified sampling conducts surveys by stratum, which is easy to operate and manage.
(2) In stratified sampling, the sampling of each stratum is relatively independent, and the overall parameter values ??of each stratum can be estimated separately.
(3) When the degree of variation in identification of each unit within each stratum of the sampling population is small, and the degree of variation in identification between strata is large, stratified sampling can significantly improve sampling efficiency.
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