It is always possible to construct a real function phi, given random quanti
ties X and Y with continuous distribution functions F and G, respectively,
in such a way that phi(X) and phi(Y), also random quantities, have both the
same distribution function, say H. This result of De Finetti introduces an
alternative way to somehow describe the `opinion' of a group of experts ab
out a continuous random quantity by the construction of Fields of coinciden
ce of opinions (FCO). A Field of coincidence of opinions is a finite union
of intervals where the opinions of the experts coincide with respect to tha
t quantity of interest. We speculate on (dis)advantages of Fields of Opinio
n compared to usual 'probability' measures of a group and on their relation
with a continuous version of the well-known Allais' paradox.