International audienceThe use of cooperative fusion systems for image interpretation according to expert knowledge has known a wide growth and they now need reliable ways to evaluate their performance. Local evaluation is an interesting way to better characterize the system behaviour and consequently to have information on which subpart needs to be adjusted. A previously proposed local evaluation based on separability indexes, generates many numerical indicators. In this paper we proposes a symbolic representation of these separability index easier to understand by the experts. To overcome the application of a threshold, the uncertainty of the numeric measures is represented thanks to possibility distributions