เปรียบเทียบวิธี

	Maximum Variation Sampling	Snowball Sampling
สาขาวิชา	ระเบียบวิธีสำรวจ	ระเบียบวิธีสำรวจ
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1985 (Lincoln & Guba); elaborated 1990–2002 (Patton)	1961
ผู้ริเริ่ม	Lincoln & Guba; systematised by Michael Quinn Patton	Leo A. Goodman
ประเภท	Purposive qualitative sampling strategy	Non-probability sampling technique
แหล่งต้นตำรับ	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage. Chapter 5: Purposeful Sampling. ISBN: 978-0761919711	Goodman, L. A. (1961). Snowball sampling. Annals of Mathematical Statistics, 32(1), 148–170.
ชื่อเรียกอื่น	maximum variation sampling, maximum diversity sampling, MVS, heterogeneous sampling	chain-referral sampling, network sampling, respondent-driven sampling, referral sampling
ที่เกี่ยวข้อง	5	3
สรุป	Maximum variation sampling is a purposive qualitative sampling strategy in which the researcher deliberately selects cases that span the widest possible range of variation on dimensions central to the study. The goal is not statistical representation but the identification of common patterns that cut across diverse cases as well as the documentation of the unique ways each context shapes the phenomenon under investigation.	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.