مقایسهٔ روش‌ها

	نمونه‌گیری هدفمند چندسطحی	نمونه‌گیری هدفمند
حوزه	روش‌شناسی پیمایش	روش‌شناسی پیمایش
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1980s–1990s	Formalized ~1980–1990
پدیدآور	Derived from Patton's purposive sampling framework; formalized in multi-site qualitative and mixed-methods research	Michael Quinn Patton (systematic articulation); roots in early qualitative inquiry
نوع	Non-probability sampling strategy	Non-probability sampling strategy
منبع بنیادین	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage. ISBN: 978-0761919711	Patton, M. Q. (1990). Qualitative Evaluation and Research Methods (2nd ed.). Sage. ISBN: 978-0803937796
نام‌های دیگر	hierarchical purposive sampling, nested purposive sampling, multi-tier purposive sampling, multi-site purposive sampling	judgmental sampling, selective sampling, criterion-based sampling, purposeful sampling
مرتبط	5	4
خلاصه	Multi-level purposive sampling applies purposive selection criteria at two or more nested levels of a research hierarchy — for instance, first selecting sites or organizations, then selecting participants within each site. This layered approach allows researchers to align the theoretical logic of purposive sampling with the real-world structure of complex, hierarchical populations, making it especially valuable in multi-site qualitative studies and mixed-methods research.	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.