So sánh phương pháp

	Kỹ thuật Delphi	Khảo sát trực diện
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1950s–1963	1930s–1940s (systematic survey era)
Người khởi xướng	Norman Dalkey and Olaf Helmer (RAND Corporation)	Established practice formalised in survey methodology (Gallup, Likert, and others from the 1930s–1940s)
Loại	Iterative expert consensus technique	Quantitative / mixed-mode data collection
Công trình gốc	Dalkey, N., & Helmer, O. (1963). An experimental application of the Delphi method to the use of experts. Management Science, 9(3), 458–467.	Fowler, F. J. (2014). Survey Research Methods (5th ed.). Sage Publications. ISBN: 978-1452259000
Tên gọi khác	Delphi method, Delphi survey, expert consensus method, iterative expert panel	personal interview survey, in-person survey, PAPI survey, door-to-door survey
Liên quan	6	5
Tóm tắt	The Delphi technique is a structured, multi-round data collection method that harvests and refines expert opinion through iterative questionnaires and controlled feedback. Developed at RAND Corporation in the 1950s, it is designed to converge a dispersed expert panel toward a reliable consensus on complex, uncertain, or future-oriented questions — without the conformity pressures of face-to-face group discussion.	A face-to-face survey is a structured data collection method in which a trained interviewer meets respondents in person and administers a standardised questionnaire. The interviewer reads questions aloud, clarifies wording when permitted by protocol, and records answers — either on paper (PAPI) or a laptop/tablet (CAPI). This mode consistently achieves higher response rates and better data quality for complex or sensitive questionnaires than self-administered alternatives, and is the reference standard in large-scale population surveys.