So sánh phương pháp

	Chọn mẫu có chủ đích trực tuyến	Lấy mẫu Biến thiên Tối đa
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1990s–2000s (with growth of internet-based research)	1985 (Lincoln & Guba); elaborated 1990–2002 (Patton)
Người khởi xướng	Adaptation of purposive sampling (Patton, 1987) to online/digital research contexts	Lincoln & Guba; systematised by Michael Quinn Patton
Loại	Non-probability qualitative sampling	Purposive qualitative sampling strategy
Công trình gốc	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage Publications. ISBN: 978-0761919711	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage. Chapter 5: Purposeful Sampling. ISBN: 978-0761919711
Tên gọi khác	internet-based purposive sampling, web purposive sampling, online criterion-based sampling, digital purposive sampling	maximum variation sampling, maximum diversity sampling, MVS, heterogeneous sampling
Liên quan	3	5
Tóm tắt	Online purposive sampling applies the logic of criterion-based participant selection to digital recruitment channels — including social media platforms, online communities, email lists, and research recruitment websites. Researchers intentionally seek individuals who possess the characteristics, experiences, or expertise directly relevant to the research question, using internet-based tools to locate and screen them. The method preserves the defining feature of purposive sampling — deliberate selection based on fitness for purpose — while leveraging the reach and accessibility of online environments.	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.