In social sciences, we need simulations in order to know how collective forms can result from complex interactions. The more complex they are – for example when integrating the effect of actors’ representations of collective forms on collective phenomena- the more divergent they can be, leading to indeterminacy. Moreover we are more sensitive to more stable, more differentiated forms, the recognition of which is easier. Combining these two trends leads us to substitute to the ideal of correspondence with social reality the comparability of simulations, in order to get means of criticizing and revising one simulation by the others. We keep in mind together the divergent scenarios that are the easier ones to be distinguished while paying attention to possible divergences that were neglected at first.