方法对比

	简单随机抽样	系统抽样
领域	调查方法论	调查方法论
方法族	Process / pipeline	Process / pipeline
起源年份	Early 20th century; systematized by Cochran 1953/1977	Mid-20th century (Cochran 1953; Kish 1965)
提出者	William Gosset, Jerzy Neyman, and formalized by William Cochran	William G. Cochran; formalized in survey sampling theory
类型	Probability sampling design	Probability sampling design
开创性文献	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
别名	SRS, unrestricted random sampling, equal-probability sampling, EPSEM	interval sampling, systematic random sampling, equal-interval sampling, fixed-interval sampling
相关	6	5
摘要	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.