The MATES 2013 conference is accompanied by the following dedicated workshop sessions on different issues of agent technology. The workshop day is held in cooperation with the fourth realization of JAWS (Joint Agent-oriented Workshops in Synergy) which builds upon synergies of interests and aims at bringing together researchers from the agent community for lively discussions and exchange of ideas. This JAWS workshop is part of the European joint event MATES+JAWS which contributions will be published in the joint proceeedings of the MATES 2013 conference.