Different techniques of fusion of information of the theory of the possibilities have been presented here:

• first, the basic elements:
• conjunctive fusion on the one hand, useful for the fusion of sources very in agreement, and
• to opposite, disjunctive fusion whose objective consists in managing the problems of conflict between sources of information.
  
  
• Then, two adaptive methods of fusion whose interest lies in their ability to modify their behaviour according to the degree of conflict between the sources, in order to deal with each problem in an adequate way.

The key element which gives an adaptive feature to these two methods is the height of the intersection of the possibility distributions given by each source:

• A high intersection indicates a strong consensus, and thus directs fusion towards a conjunctive behaviour.
• A weak intersection, on the contrary, means that the sources are in conflict. A fusion of the disjunctive type is then used.

The disadvantage of these methods is their nonassociative character due to the calculation of the height of the intersection of possibility distributions. This implies that adaptive fusion methods are likely to provide different results according to the way sources of information are merged. But this problem is avoided if all the sources are merged at the same time.

• Finally, a method of fusion managing the priorities given to each source. The goal here is to give the preference to the sources judged to be most reliable when there is a conflict to solve. If there is conflict, then the least reliable sources are mistaken.