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	Delphi Technology Forecasting	Trend Impact Analysis
Campo	Futures Foresight Studies	Futures Foresight Studies
Famiglia	Process / pipeline	Process / pipeline
Anno di origine	1964	1972
Ideatore	Olaf Helmer, Norman Dalkey, and colleagues at the RAND Corporation	Theodore J. Gordon (The Futures Group / Millennium Project)
Tipo	Iterative anonymous expert-panel pipeline for forecasting technological events	Probabilistic trend-extrapolation pipeline perturbed by future events
Fonte seminale	Glenn, J. C., & Gordon, T. J. (Eds.). (2009). Futures Research Methodology, Version 3.0. The Millennium Project. ISBN: 9780981894119	Gordon, T. J., & Hayward, H. (1968). Initial experiments with the cross-impact matrix method of forecasting. Futures, 1(2), 100-116.
Alias	Technological Delphi, RAND Delphi Forecasting, Expert Panel Technology Forecasting, Delphi Event Forecasting	TIA, Trend-Impact Forecasting, Probabilistic Trend Perturbation, Event-Adjusted Trend Extrapolation
Correlati	3	3
Sintesi	Delphi technology forecasting is the original and best-known application of the Delphi method: using iterative, anonymous rounds of expert judgment with controlled statistical feedback to forecast the timing and probability of specific technological developments. Developed at the RAND Corporation by Olaf Helmer, Norman Dalkey, and colleagues, the technique was designed to harness expert opinion systematically while suppressing the social pressures of face-to-face committees — dominant personalities, bandwagon effects, and reluctance to abandon a stated position. Rather than asking a panel for a general opinion, technological Delphi asks experts to predict the year by which a well-defined development will occur, or the probability that it will occur by a given date, and then feeds back the panel's median and spread so that experts can reconsider in light of the group. Glenn and Gordon's Futures Research Methodology treats it as a foundational structured-judgment method of the field.	Trend impact analysis (TIA) is a forecasting method that marries quantitative extrapolation with expert judgment about disruptive future events. Developed by Theodore Gordon and colleagues at The Futures Group in the early 1970s and later codified in the Millennium Project's Futures Research Methodology, it starts from a 'surprise-free' baseline produced by fitting and projecting a historical time series. It then asks which unprecedented events — events with no historical analog that ordinary extrapolation cannot anticipate — could deflect that trend, and with what probability, magnitude, and timing. Through Monte Carlo simulation those probabilistic impacts perturb the baseline, yielding not a single line but a probability envelope that shows how the trend might bend if the unexpected occurs.