So sánh phương pháp

	Lấy mẫu hệ thống có trọng số	Lấy mẫu có hệ thống
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	Mid-20th century (1950s-1970s)	Mid-20th century (Cochran 1953; Kish 1965)
Người khởi xướng	William G. Cochran (systematic and weighted probability sampling theory)	William G. Cochran; formalized in survey sampling theory
Loại	Probability sampling technique	Probability sampling design
Công trình gốc	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0471162407	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons. ISBN: 978-0471162407
Tên gọi khác	systematic sampling with weights, probability-weighted systematic sampling, systematic PPS sampling	interval sampling, systematic random sampling, equal-interval sampling, fixed-interval sampling
Liên quan	5	5
Tóm tắt	Weighted systematic sampling selects units at equal spacing along a cumulative-weight axis rather than along a simple list index. By ordering the population and accumulating auxiliary size or importance weights before applying a fixed sampling interval, it combines the operational simplicity of systematic sampling with the efficiency gains of probability-proportional-to-size selection — giving larger or more important units a higher probability of inclusion while still visiting every part of the ordered frame.	Systematic sampling is a probability sampling technique in which every k-th element is selected from an ordered list of the population after a random starting point. With population size N and desired sample size n, the sampling interval k = N/n is computed and one unit is chosen at random from the first interval; all subsequent units are selected by adding k repeatedly. The method is operationally simple, yields a spread-out sample, and often achieves lower variance than simple random sampling when the list has no harmful periodicity.