So sánh phương pháp

	Chọn mẫu hạn ngạch	Chọn mẫu phân tầng tỷ lệ
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1930s	1953–1965 (formalized in survey sampling literature)
Người khởi xướng	Developed in market research and opinion polling, notably applied by George Gallup in the 1930s	William G. Cochran; Leslie Kish
Loại	Non-probability sampling design	Probability sampling design
Công trình gốc	Moser, C. A., & Kalton, G. (1972). Survey Methods in Social Investigation (2nd ed.). Heinemann. ISBN: 978-0435827496	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons. ISBN: 978-0471162407
Tên gọi khác	quota-controlled sampling, quota selection, non-probability quota sampling	proportionate stratified sampling, proportional allocation stratified sampling, PSRS, proportionate stratified random sampling
Liên quan	5	6
Tóm tắt	Quota sampling is a non-probability technique in which the researcher pre-specifies how many units to recruit from each subgroup (quota cell) defined by one or more control variables such as age, gender, or occupation. Interviewers or data collectors then use their own judgment to find and enroll participants until each cell is filled. The method guarantees the sample mirrors the population on the control variables but does not provide the randomness needed for classical statistical inference.	Proportional stratified sampling divides the target population into non-overlapping strata (subgroups defined by a key characteristic such as age band, region, or gender) and then draws a simple random sample from each stratum so that each stratum's share of the total sample matches its share of the total population. Because each subgroup is represented in exact proportion to its population weight, the resulting sample mirrors the population structure closely without requiring post-hoc weighting adjustments.