เปรียบเทียบวิธี

	การเลือกตัวอย่างกรณีที่เบี่ยงเบน	การสุ่มตัวอย่างกรณีทั่วไป
สาขาวิชา	ระเบียบวิธีสำรวจ	ระเบียบวิธีสำรวจ
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1990	1980s (systematized in Patton 1990/2002)
ผู้ริเริ่ม	Michael Quinn Patton	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	extreme case sampling, outlier sampling, negative case sampling, deviant-case selection	typical case selection, modal case sampling, representative case sampling, average case sampling
ที่เกี่ยวข้อง	5	5
สรุป	Deviant case sampling is a purposive qualitative sampling strategy in which the researcher intentionally selects cases that are unusual, exceptional, or markedly different from the norm — outliers, extreme successes, or conspicuous failures. The goal is not statistical representation but deep learning from cases that illuminate the boundaries of a phenomenon, challenge prevailing assumptions, or reveal processes that typical cases obscure.	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.