A way of estimating future measures by asking a group of experts to make estimates, recirculating the estimates back to the group, and repeating the process till the numbers converge. Often used for estimating when an event might occur - e.g. "In what year will the majority of households in OECD countries have broadband internet access?" Developed in the 1950s by Harold Linstone and Murray Turoff, and widely used, specially in Japan.

A qualitative forecasting technique where the opinions of experts are combined in a series of iterations. The results of each iteration are used to develop the next, so that convergence of the experts' opinions is obtained. See: management estimation, panel consensus.

A centralised forecasting method that takes into account the views of managers, sales personnel and individual participants; aggregates them; and modifies them. p. 707