So sánh phương pháp

	Chọn mẫu có chủ đích theo tỷ lệ	Chọn mẫu phân tầng tỷ lệ
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1980s–2000s	1953–1965 (formalized in survey sampling literature)
Người khởi xướng	Derived from purposive sampling tradition (Patton); formalized in mixed-methods literature	William G. Cochran; Leslie Kish
Loại	Non-probability sampling with proportional allocation	Probability sampling design
Công trình gốc	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage Publications. ISBN: 978-0761919711	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons. ISBN: 978-0471162407
Tên gọi khác	proportional criterion sampling, quota-proportional purposive sampling, representational purposive sampling	proportionate stratified sampling, proportional allocation stratified sampling, PSRS, proportionate stratified random sampling
Liên quan	4	6
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.	Proportional stratified sampling divides the target population into non-overlapping strata (subgroups defined by a key characteristic such as age band, region, or gender) and then draws a simple random sample from each stratum so that each stratum's share of the total sample matches its share of the total population. Because each subgroup is represented in exact proportion to its population weight, the resulting sample mirrors the population structure closely without requiring post-hoc weighting adjustments.