مقایسهٔ روش‌ها

	نظریه داده‌بنیاد	نمونه‌گیری هدفمند
حوزه	پژوهش کیفی	روش‌شناسی پیمایش
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1967	Formalized ~1980–1990
پدیدآور	Barney Glaser and Anselm Strauss	Michael Quinn Patton (systematic articulation); roots in early qualitative inquiry
نوع	Method	Non-probability sampling strategy
منبع بنیادین	Glaser, B. G., & Strauss, A. L. (1967). The discovery of grounded theory: Strategies for qualitative research. Aldine.	Patton, M. Q. (1990). Qualitative Evaluation and Research Methods (2nd ed.). Sage. ISBN: 978-0803937796
نام‌های دیگر	GT, Grounded Theory Approach	judgmental sampling, selective sampling, criterion-based sampling, purposeful sampling
مرتبط	3	4
خلاصه	Grounded Theory (GT) is a systematic qualitative research methodology in which theory emerges directly from data through iterative analysis, rather than being imposed before data collection. Developed by Barney Glaser and Anselm Strauss in 1967, GT prioritizes generating explanatory frameworks grounded in evidence.	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.