So sánh phương pháp

	Lấy mẫu ngẫu nhiên đơn giản	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	Early 20th century; systematized by Cochran 1953/1977	Mid-20th century (Cochran 1953; Kish 1965)
Người khởi xướng	William Gosset, Jerzy Neyman, and formalized by William Cochran	William G. Cochran; formalized in survey sampling theory
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	SRS, unrestricted random sampling, equal-probability sampling, EPSEM	interval sampling, systematic random sampling, equal-interval sampling, fixed-interval sampling
Liên quan	6	5
Tóm tắt	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.	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.