Σύγκριση μεθόδων

	Τεχνική Delphi	Συνέντευξη πρόσωπο με πρόσωπο	Μεικτή Έρευνα (Mixed Methods Research)
Πεδίο	Μεθοδολογία Επισκοπήσεων	Μεθοδολογία Επισκοπήσεων	Ποιοτικές Μέθοδοι
Οικογένεια	Process / pipeline	Process / pipeline	Process / pipeline
Έτος προέλευσης	1950s–1963	1930s–1940s (systematic survey era)	—
Δημιουργός	Norman Dalkey and Olaf Helmer (RAND Corporation)	Established practice formalised in survey methodology (Gallup, Likert, and others from the 1930s–1940s)	—
Τύπος	Iterative expert consensus technique	Quantitative / mixed-mode data collection	Research design framework
Θεμελιώδης πηγή	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	Creswell, J.W. & Plano Clark, V.L. (2018). Designing and Conducting Mixed Methods Research (3rd ed.). Sage. ISBN: 978-1483344379
Εναλλακτικές ονομασίες	Delphi method, Delphi survey, expert consensus method, iterative expert panel	personal interview survey, in-person survey, PAPI survey, door-to-door survey	Karma Yöntem Araştırması (Mixed Methods), multi-method research, triangulation design
Συναφείς	6	5	4
Σύνοψη	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.	Mixed methods research is a systematic research design in which quantitative and qualitative data are collected and analysed within a single study. Formalised by Creswell and Plano Clark (2003, 3rd ed. 2018), it offers three principal design variants — concurrent, sequential, and transformative — and strengthens findings through triangulation across both data strands.