We want to thank all the authors of the position papers for their insightful talks during the workshop and their very interesting submissions. We also thank all the participants for their active attendance, and sound questions and debates during the plenary sessions and the roundtable. We are particularly grateful to all the discussants that have contributed to this Special Issue for their thought-provoking comments. We are indebted to Prof. Denœux for welcoming and actively participating to this special issue, and for his constant support during the whole process. The workshop has been supported by the Spanish project TIN2011-24302. We gratefully acknowledge this support.