So sánh phương pháp

	Lấy Mẫu Hệ Thống Tỷ Lệ	Chọn mẫu nhiều giai đoạn
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)	1950s–1960s (formalized in Kish 1965 and Cochran 1977)
Người khởi xướng	Codified in classical survey sampling theory; see Cochran (1977)	Leslie Kish; William G. Cochran
Loại	Probability sampling design	Probability sampling design
Công trình gốc	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0471162407	Kish, L. (1965). Survey Sampling. John Wiley & Sons. ISBN: 978-0471109495
Tên gọi khác	proportional 1-in-k sampling, equal-probability systematic sampling, proportionate systematic selection, PPS systematic sampling	multistage cluster sampling, multi-stage sampling, nested sampling, hierarchical sampling
Liên quan	6	5
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.	Multistage sampling is a probability-based design that selects a sample by working through two or more successive levels of a population hierarchy — for example, first selecting regions, then districts within those regions, then households within those districts. It makes large-scale surveys practical when a complete population list is unavailable or when the population is geographically dispersed, by concentrating fieldwork within a manageable number of sampled units at each stage.