Сравнение на методи

	Многостепенно удобствово извадково изследване	Целенасочено подбиране
Област	Методология на проучванията	Методология на проучванията
Семейство	Process / pipeline	Process / pipeline
Година на възникване	1980s–1990s (concurrent with multilevel modeling development)	Formalized ~1980–1990
Създател	Emerged from multilevel/hierarchical research traditions	Michael Quinn Patton (systematic articulation); roots in early qualitative inquiry
Тип	Non-probability sampling design	Non-probability sampling strategy
Основополагащ източник	Hox, J. J. (2010). Multilevel Analysis: Techniques and Applications (2nd ed.). Routledge. ISBN: 978-1848728462	Patton, M. Q. (1990). Qualitative Evaluation and Research Methods (2nd ed.). Sage. ISBN: 978-0803937796
Други названия	hierarchical convenience sampling, nested convenience sampling, multilevel accessibility sampling, multi-tier convenience sampling	judgmental sampling, selective sampling, criterion-based sampling, purposeful sampling
Свързани	5	4
Резюме	Multi-level convenience sampling is a non-probability approach in which units are selected by convenience at each of two or more nested levels of a hierarchy — for example, recruiting whatever schools agree to participate and then enrolling all available students within those schools. It is widely used in organizational, educational, and health research where the researcher has limited control over access but must respect the nested structure of the population.	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.