So sánh phương pháp

	Chọn mẫu có chủ đích theo tỷ lệ	Chọn mẫu có chủ đích
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1980s–2000s	Formalized ~1980–1990
Người khởi xướng	Derived from purposive sampling tradition (Patton); formalized in mixed-methods literature	Michael Quinn Patton (systematic articulation); roots in early qualitative inquiry
Loại	Non-probability sampling with proportional allocation	Non-probability sampling strategy
Công trình gốc	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage Publications. ISBN: 978-0761919711	Patton, M. Q. (1990). Qualitative Evaluation and Research Methods (2nd ed.). Sage. ISBN: 978-0803937796
Tên gọi khác	proportional criterion sampling, quota-proportional purposive sampling, representational purposive sampling	judgmental sampling, selective sampling, criterion-based sampling, purposeful sampling
Liên quan	4	4
Tóm tắt	Proportional purposive sampling combines the intentional case selection of purposive sampling with proportional allocation across subgroups. Researchers first determine how each meaningful subgroup (e.g., gender, school type, professional role) is represented in the population, then deliberately select participants from each subgroup in those same proportions — using purposive judgment to ensure each selected case is information-rich and relevant to the research question.	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.