Módszerek összehasonlítása

	Delphi módszer	Longitudinal Survey
Tudományterület	Kérdőíves felmérések módszertana	Kérdőíves felmérések módszertana
Módszercsalád	Process / pipeline	Process / pipeline
Keletkezés éve	1950s–1963	1940s (panel survey tradition); longitudinal designs codified mid-20th century
Megalkotó	Norman Dalkey and Olaf Helmer (RAND Corporation)	Established tradition; formalized in social science by Paul Lazarsfeld and colleagues (1940s panel studies)
Típus	Iterative expert consensus technique	Quantitative / mixed-methods survey design
Alapmű	Dalkey, N., & Helmer, O. (1963). An experimental application of the Delphi method to the use of experts. Management Science, 9(3), 458–467.	Menard, S. (2002). Longitudinal Research (2nd ed.). Sage Publications. ISBN: 978-0761922292
Alternatív nevek	Delphi method, Delphi survey, expert consensus method, iterative expert panel	panel survey, repeated-measures survey, longitudinal panel study, wave survey
Kapcsolódó	6	3
Összefoglaló	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 longitudinal survey collects structured questionnaire data from the same individuals or units at two or more distinct points in time. By tracking the same respondents across waves, researchers can distinguish genuine change from stable individual differences, establish temporal ordering between variables, and model trajectories of attitudes, behaviors, or outcomes in ways that a single cross-sectional snapshot cannot support.