So sánh phương pháp

	Chọn mẫu thuận tiện dựa trên địa điểm thực địa	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	Conventional practice in social and epidemiological field research	Developed in market research and opinion polling, notably applied by George Gallup in the 1930s
Loại	Non-probability sampling	Non-probability sampling design
Công trình gốc	Babbie, E. (2010). The Practice of Social Research (12th ed.). Wadsworth Cengage Learning. ISBN: 978-0495598428	Moser, C. A., & Kalton, G. (1972). Survey Methods in Social Investigation (2nd ed.). Heinemann. ISBN: 978-0435827496
Tên gọi khác	intercept sampling, on-site convenience sampling, street intercept sampling, field intercept survey	quota-controlled sampling, quota selection, non-probability quota sampling
Liên quan	4	5
Tóm tắt	Field-based convenience sampling is a non-probability technique in which researchers recruit participants by approaching whoever is physically present and accessible at a chosen real-world location — a market, hospital waiting room, park, or transit hub. It is widely used in public health surveillance, marketing research, and exploratory social surveys when rapid, low-cost data collection is needed and probability sampling is not feasible.	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.