Epistemic probabilities in argumentation frameworks are meant to
represent subjective degrees of belief in the acceptance of arguments. As such,
they are subject to some rationality conditions, taking into account the attack
relation between arguments. This paper provides an advancement with respect to
the previous literature on this matter by casting epistemic probabilities in
the context of de Finetti’s theory of subjective
probability and by analyzing and revising the relevant rationality properties
in relation with de Finetti’s notion of coherence.
Further, we consider the extension to Walley’s theory
of imprecise probabilities and carry out a preliminary analysis about
rationality conditions in this more general context.