So sánh phương pháp

	Lấy mẫu hệ thống có trọng số	Lấy mẫu ngẫu nhiên đơn giản
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)	Early 20th century; systematized by Cochran 1953/1977
Người khởi xướng	William G. Cochran (systematic and weighted probability sampling theory)	William Gosset, Jerzy Neyman, and formalized by William Cochran
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	SRS, unrestricted random sampling, equal-probability sampling, EPSEM
Liên quan	5	6
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.	Simple random sampling (SRS) is the foundational probability sampling method in which every unit in the population has an equal and independent chance of being selected. Because selection is governed purely by chance, SRS eliminates systematic bias, supports unbiased estimation of population parameters, and provides the statistical baseline against which all more complex probability designs are evaluated.