手法を比較

	単純無作為抽出法	層化抽出法
分野	調査方法論	調査方法論
系統	Process / pipeline	Process / pipeline
提唱年	Early 20th century; systematized by Cochran 1953/1977	1977
提唱者	William Gosset, Jerzy Neyman, and formalized by William Cochran	William G. Cochran
種類	Probability sampling design	Probability-based survey sampling design
原典	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons. ISBN: 978-0471162407	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0-471-16240-7
別名	SRS, unrestricted random sampling, equal-probability sampling, EPSEM	Proportional Stratified Sampling, Optimal Allocation Sampling, Stratum-Based Sampling, Tabakalı Örnekleme
関連	6	2
概要	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.	Stratified sampling is a probability sampling design in which the target population is partitioned into non-overlapping, exhaustive subgroups called strata, and independent probability samples are drawn within each stratum. Formalized by William G. Cochran in Sampling Techniques (1977), the method exploits known population structure to reduce variance and guarantee representativeness of all major subgroups, making it a cornerstone of large-scale survey research and official statistics.