Santa Barbara. Learning how to change the opinions of individuals over time by using a mathematical model. This is what an international research group formed by the Institute of Electronic and Information Engineering and Telecommunications of the National Research Council of Turin (IEIIT-CNR), in collaboration with the University of California, Santa Barbara (USA), Delft University of Technology (Netherlands) and the Russian Academy of Sciences with a publication on ‘Science’ journal. The new model has been tested with a quantitative analysis of the causes that led to the US military invasion in Iraq in 2003, but can also forecast future evolution of social phenomena. (9Colonne)