So sánh phương pháp

	Lấy mẫu thuận tiện theo tỷ lệ	Chọn mẫu hạn ngạch
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	Mid-20th century onward	1930s
Người khởi xướng	Developed within mainstream sampling methodology; no single originator	Developed in market research and opinion polling, notably applied by George Gallup in the 1930s
Loại	Non-probability sampling with proportional allocation constraint	Non-probability sampling design
Công trình gốc	Etikan, I., & Bala, K. (2017). Sampling and sampling methods. Biometrics & Biostatistics International Journal, 5(6), 215–217.	Moser, C. A., & Kalton, G. (1972). Survey Methods in Social Investigation (2nd ed.). Heinemann. ISBN: 978-0435827496
Tên gọi khác	quota-constrained convenience sampling, representative convenience sampling, proportionate accidental sampling, PCS	quota-controlled sampling, quota selection, non-probability quota sampling
Liên quan	4	5
Tóm tắt	Proportional convenience sampling is a non-probability technique that recruits participants through convenience while constraining each subgroup's share in the final sample to match its known proportion in the target population. It trades pure random selection for feasibility, but partially compensates by ensuring the sample's compositional profile mirrors the population on one or more key variables such as gender, age group, or academic year.	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.