The Delphi method was originally developed in the 50s by the RAND Corporation in Santa Monica. This approach consists of a survey conducted in two or more rounds and provides the participants in the second round with the results of the first so that they can alter the oroginal assessments if they want to - or stick to their previous opinion. Nobody 'looses face' because the survey is done anonymously using a questionnaire (the first Delphis were panels). It is commonly assumed that the method makes better use of group interaction whereby the questionnaire is the medium of interaction. The Delphi method is especially useful for long-range forecasting (20-30 years), as expert opinions are the only source of information available. Meanwhile, the communication effect of Delphi studies and therefore the value of the process as such is also acknowledged.

During the last ten years, the Delphi method was used more often especially for national science and technolog foresight. Delphi studies are rather complex procedures and require some resources depending on the breadth of the study planned.