مقایسهٔ روش‌ها

	نمونه‌گیری در دسترس مبتنی بر میدان	نمونه‌گیری گلوله‌برفی
حوزه	روش‌شناسی پیمایش	روش‌شناسی پیمایش
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	Mid-20th century onward	1961
پدیدآور	Conventional practice in social and epidemiological field research	Leo A. Goodman
نوع	Non-probability sampling	Non-probability sampling technique
منبع بنیادین	Babbie, E. (2010). The Practice of Social Research (12th ed.). Wadsworth Cengage Learning. ISBN: 978-0495598428	Goodman, L. A. (1961). Snowball sampling. Annals of Mathematical Statistics, 32(1), 148–170.
نام‌های دیگر	intercept sampling, on-site convenience sampling, street intercept sampling, field intercept survey	chain-referral sampling, network sampling, respondent-driven sampling, referral sampling
مرتبط	4	3
خلاصه	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.	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.