So sánh phương pháp

	Phương pháp chọn mẫu Snowball dựa trên thực địa	Lấy mẫu chuỗi giới thiệu – Lấy mẫu quả cầu tuyết
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1961 (foundational); field variant developed through 1970s–1980s ethnographic and hidden population research	1961
Người khởi xướng	Leo A. Goodman (snowball sampling); field adaptation through ethnographic and social network research traditions	Leo A. Goodman
Loại	Non-probability sampling technique	Non-probability sampling technique
Công trình gốc	Goodman, L. A. (1961). Snowball sampling. Annals of Mathematical Statistics, 32(1), 148–170.	Goodman, L. A. (1961). Snowball sampling. Annals of Mathematical Statistics, 32(1), 148–170.
Tên gọi khác	in-person snowball sampling, fieldwork chain-referral sampling, field snowball sampling, face-to-face referral sampling	chain-referral sampling, network sampling, respondent-driven sampling, referral sampling
Liên quan	3	3
Tóm tắt	Field-based snowball sampling is a non-probability chain-referral technique in which an initial set of in-person contacts (seeds) recruit further participants from within their real-world social networks, expanding the sample iteratively through face-to-face interaction in naturalistic field settings. It is the default snowball approach in ethnographic and community fieldwork, and is particularly valuable when the target population is hidden, hard-to-reach, or lacks a sampling frame.	Snowball sampling is a non-probability recruitment technique in which initial participants (seeds) refer the researcher to others who meet the study criteria, and those referrals in turn refer further participants. The sample grows incrementally — like a rolling snowball — until the required size or theoretical saturation is reached. It is the method of choice when a target population has no accessible sampling frame, such as undocumented migrants, illicit drug users, survivors of stigmatised experiences, or members of closed professional networks.