So sánh phương pháp

	Lấy mẫu có hệ thống	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 (Cochran 1953; Kish 1965)	Early 20th century; systematized by Cochran 1953/1977
Người khởi xướng	William G. Cochran; formalized in survey sampling theory	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.). John Wiley & Sons. ISBN: 978-0471162407	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons. ISBN: 978-0471162407
Tên gọi khác	interval sampling, systematic random sampling, equal-interval sampling, fixed-interval sampling	SRS, unrestricted random sampling, equal-probability sampling, EPSEM
Liên quan	5	6
Tóm tắt	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.	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.