เปรียบเทียบวิธี

	การเลือกตัวอย่างกรณีเบี่ยงเบนตามบริบทภาคสนาม	การสุ่มตัวอย่างกรณีทั่วไป
สาขาวิชา	ระเบียบวิธีสำรวจ	ระเบียบวิธีสำรวจ
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1980s–1990s (purposive/deviant case sampling literature)	1980s (systematized in Patton 1990/2002)
ผู้ริเริ่ม	Michael Quinn Patton; Yvonna Lincoln & Egon Guba	Michael Quinn Patton
ประเภท	Purposive qualitative sampling strategy	Purposive qualitative sampling strategy
แหล่งต้นตำรับ	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage Publications. ISBN: 978-0761919711	Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage Publications. ISBN: 978-0761919711
ชื่อเรียกอื่น	field deviant case sampling, outlier case sampling in field research, extreme case sampling in fieldwork, in-situ deviant case sampling	typical case selection, modal case sampling, representative case sampling, average case sampling
ที่เกี่ยวข้อง	5	5
สรุป	Field-based deviant case sampling is a purposive strategy that deliberately selects cases deviating markedly from an established pattern or norm, with data collected through direct fieldwork — observation, in-situ interviews, and ethnographic engagement — in the participants' natural settings. By studying outliers on-site, researchers gain contextually grounded insight into why and how certain cases diverge from the typical pattern.	Typical case sampling is a purposive strategy in which the researcher deliberately selects cases that represent what is ordinary, normal, or most common within a target group. Rather than seeking outliers or the widest possible variation, the goal is to illustrate and communicate what a typical experience, program, or phenomenon looks like to stakeholders or audiences unfamiliar with it. The strategy is widely used in qualitative evaluation research and program reporting.