The method is three-fold:
1. The phenomenon of the wisdom of crowds; from the well-known Galton experiment (1907) to Surowiecki's studies 'The Wisdom of Crowds (2004-2010);
2. The Shang method, published by Ford in 1975;
3. The face-to-face interrogation in groups of experts, with the Pfizer method (1978) perfected by Galleri (2007-2014).
In writing the book Prevedere per Decidere, Marco Galleri considered the general and particular aspects of rational predictive methods and he conceived the Crowdshang idea, where the binary surveys, previously submitted to thousands of people, are perfected by a group of trained experts.
The idea is quite simple: the worth of the Shang method is greatly enhanced by the wisdom of a huge crowd; the common sense of the analysts and the coordinator plays any differences that could improve this method. On the other hand: in a huge crowd, you can find large numbers of specialists and thus obtain correct surveys.