So sánh phương pháp

	Lấy Mẫu Hệ Thống Tỷ Lệ	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 (formalized ~1950s–1970s)	Early 20th century; systematized by Cochran 1953/1977
Người khởi xướng	Codified in classical survey sampling theory; see Cochran (1977)	William Gosset, Jerzy Neyman, and formalized by William Cochran
Loại	Probability sampling design	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	proportional 1-in-k sampling, equal-probability systematic sampling, proportionate systematic selection, PPS systematic sampling	SRS, unrestricted random sampling, equal-probability sampling, EPSEM
Liên quan	6	6
Tóm tắt	Proportional systematic sampling combines systematic (every k-th element) selection with proportional allocation across subgroups, ensuring that each stratum contributes sample units in proportion to its share of the total population. The result is an equal-probability design that is administratively simple, spreads the sample evenly across an ordered frame, and eliminates the need for post-hoc weighting when strata are sampled at a uniform rate.	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.