So sánh phương pháp

	Chọn Mẫu Có Chủ Đích Đa Cấp	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	1980s–1990s	1985 (Lincoln & Guba); elaborated 1990–2002 (Patton)
Người khởi xướng	Derived from Patton's purposive sampling framework; formalized in multi-site qualitative and mixed-methods research	Lincoln & Guba; systematised by Michael Quinn Patton
Loại	Non-probability sampling strategy	Purposive qualitative sampling strategy
Công trình gốc	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage. 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	hierarchical purposive sampling, nested purposive sampling, multi-tier purposive sampling, multi-site purposive sampling	maximum variation sampling, maximum diversity sampling, MVS, heterogeneous sampling
Liên quan	5	5
Tóm tắt	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.	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.