方法对比

	在线目的性抽样	最大变异抽样	目的性抽样
领域	调查方法论	调查方法论	调查方法论
方法族	Process / pipeline	Process / pipeline	Process / pipeline
起源年份	1990s–2000s (with growth of internet-based research)	1985 (Lincoln & Guba); elaborated 1990–2002 (Patton)	Formalized ~1980–1990
提出者	Adaptation of purposive sampling (Patton, 1987) to online/digital research contexts	Lincoln & Guba; systematised by Michael Quinn Patton	Michael Quinn Patton (systematic articulation); roots in early qualitative inquiry
类型	Non-probability qualitative sampling	Purposive qualitative sampling strategy	Non-probability sampling strategy
开创性文献	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	Patton, M. Q. (1990). Qualitative Evaluation and Research Methods (2nd ed.). Sage. ISBN: 978-0803937796
别名	internet-based purposive sampling, web purposive sampling, online criterion-based sampling, digital purposive sampling	maximum variation sampling, maximum diversity sampling, MVS, heterogeneous sampling	judgmental sampling, selective sampling, criterion-based sampling, purposeful sampling
相关	3	5	4
摘要	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.	Purposive sampling is a non-probability strategy in which the researcher deliberately selects participants, documents, or cases that are information-rich with respect to the research question. Rather than drawing units at random, the researcher applies explicit criteria aligned with the study's purpose, maximising the depth and relevance of the data collected. It is the default sampling logic in most qualitative research designs and is also used in mixed-methods and applied evaluative work.