This special issue of the International Journal of Approximate Reasoning (IJAR) grew out of the 8th International Symposium on Imprecise Probability: Theories and Applications (ISIPTA’13). The symposium was organized by the Society for Imprecise Probability: Theories

the 8th International Symposium on Imprecise Probability: Theories and Applications (ISIPTA’13). The symposium was organized by the Society for Imprecise Probability: Theories and Applications (SIPTA) at the University of Compiègne (France) in July 2013 (http://www.sipta.org/isipta13). The biennial ISIPTA meetings are well established among international conferences on generalized methods for uncertainty quantification. The first ISIPTA took place in Gent in 1999, followed by meetings in Cornell, Lugano, Carnegie Mellon, Prague, Durham and Innsbruck. Compiègne proved to be a very nice location for ISIPTA 2013, offering wonderful opportunities for collaborations and discussions, as well as sightseeing places such as its Napoleonian palace.