Andreas Graefe and Scott Armstrong report on results from an experiment on the relative accuracy of three structured approaches compared to traditional face-to-face meetings. The four methods were compared on a quantitative judgment task that did not involve widely dispersed information among participants.
Overall, Delphi performed best, followed by nominal groups, prediction markets and unstructured meetings. Of the three structured approaches, only Delphi outperformed a simple average of participants' prior individual estimates.
The authors also report participant's ratings of the group methods. Participants preferred personal interaction such as in meetings and nominal groups. Prediction markets were rated least favorable.
The pre-print version of the paper, which will be published by the International Journal of Forecasting, is available here.
For the eighth year running the International Institute of Forecasters is offering two $5,000 grants, funded by the SAS Institute, to support research on how to improve forecasting methods and business forecasting practice. For more information on the SAS Grants, visit the Researchers Page.
When uncertainty is high and the situation is complex and not well understood, it is hard to beat a simple no-change forecast. Applying that principle to problem of long term forecasting of global average temperatures, Scott Armstrong challenged former Vice President Al Gore to bet his dramatic forecasts of dangerous manmade global warming against a no-change benchmark in 2007. Mr Gore did not accept the bet, but what if he had? We now have two years of monthly data since the challenge was issued, and Mr Gore's prediction (assumed to be an increase of 0.03C per year) was less accurate than assuming the temperature would not change from the 2007 average for both years. Mr Gore's forecast was more accurate in only four of the 24 months. To read more, visit The Global Warming Challenge site.
The Program Committee of the International Symposium on Forecasting (ISF) 2010 invites the submission of abstracts related to the theory and practice of forecasting. The deadline for abstract submission is 1 March 2010. The 30th ISF will take place in San Diego, CA, U.S.A. on June 20-23, 2010. For more information visit the symposium site.