Group-Based Forecasting Methods

Contrary to FTF meetings and NGT, under the third method, the Delphi method (also referred to as Delphi process), the group members do not have to be all in the same location, even though they continue to communicate with eaeh other. Developed by Norman Dalkey and his colleagues at the RAND Corporation in the 

and Tindale, R.S. (2011) Group-based forecasting A social psychological analysis , International Journal of Forecasting, iq-. 14-40 (hereinafter, Kerr and Tindale, Group-based forecasting ). 

Van de Ven and Delbecq, The Effectiveness. Note, however, that it is also considered that Delphi is a variant of FTF meetings. See Kerr and Tindale, Group-based forecasting , p. 18. 

The facilitator. .. produces a summary of the panel s forecasts, along with their justifications for the forecasts. The panel members are anonymous in this summary (and any subsequent summaries.) The summary is then returned to the panel members, and they are allowed to update their forecasts (if they choose) and send a new forecast (along with justifications, counterarguments, etc.) to the facilitator. This process may be repeated for more rounds. Usually, the panels forecasts converge over the rounds. A compound decision rule (one rule for when to stop, and another for how to statistically aggregate the final set of forecasts) ends the process.  

The fifth and final method involves decentralising the decision-making process in aggregating the collective wisdom of a (much larger) group. A decision, commonly referred to as prediction, market is a platform the participants use to purchase and 

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