Abstract Games of Argumentation Strategy and Game-Theoretical Argument Strength

We define a generic notion of abstract games of argumentation strategy for (attack-only and bipolar) argumentation frameworks, which are zero-sum games whereby two players put forward sets of arguments and get a reward for their combined choices. The value of these games, in the classical game-theoretic sense, can be used to define measures of (quantitative) game-theoretic strength of arguments, which are different depending on whether either or both players have an “agenda” (i.e. an argument they want to be accepted). We show that this general scheme captures as a special instance a previous proposal in the literature (single agenda, attack-only frameworks), and seamlessly supports the definition of a spectrum of novel measures of game-theoretic strength where both players have an agenda and/or bipolar frameworks are considered. We then discuss the applicability of these instances of game-theoretic strength in different contexts and analyse their basic properties

Dialogue games for explaining medication choices

SMT solvers can be used efficiently to search for optimal paths across multiple graphs when optimising for certain resources. In the medical context, these graphs can represent treatment plans for chronic conditions where the optimal paths across all plans under consideration are the ones which minimize adverse drug interactions. The SMT solvers, however, work as a black-box model and there is a need to justify the optimal plans in a human-friendly way. We aim to fulfill this need by proposing explanatory dialogue protocols based on computational argumentation to increase the understanding and trust of humans interacting with the system. The protocols provide supporting reasons for nodes in a path and also allow counter reasons for the nodes not in the graph, highlighting any potential adverse interactions during the dialogue.Postprin

Semi-stable semantics

In this article, we examine an argument-based semantics called semi-stable semantics. Semi-stable semantics is quite close to traditional stable semantics in the sense that every stable extension is also a semi-stable extension. One of the advantages of semi-stable semantics is that for finite argumentation frameworks there always exists at least one semi-stable extension. Furthermore, if there also exists at least one stable extension, then the semi-stable extensions coincide with the stable extensions. Semi-stable semantics can be seen as a general approach that can be applied to abstract argumentation, as well as to fields like default logic and answer set programming, yielding an interpretation with properties very similar to those of paraconsistent logic, including the properties of crash resistance and backward compatibility.2251207125

A discussion game for grounded semantics

We introduce an argument-based discussion game where the ability to win the game for a particular argument coincides with the argument being in the grounded extension. Our game differs from previous work in that (i) the number of moves is linear (instead of exponential) w.r.t. the strongly admissible set that the game is constructing, (ii) winning the game does not rely on cooperation from the other player (that is, the game is winning strategy based), (iii) a single game won by the proponent is sufficient to show grounded membership, and (iv) the game has a number of properties that make it more in line with natural discussion

A target-oriented discussion framework to support dollective decision making

Argumentative debates are a powerful tool for resolving conflicts and reaching agreements in open environments such as on-line communities. Here we introduce an argumentation framework to structure argumentative debates. Our framework represents the arguments issued by the participants involved in a debate, the (attack and defence) relationships between them, as well as participants’ opinions on them. Furthermore, we tackle the problem of computing a collective decision from participants’ opinions. With this aim, we design an aggregation function to ensure that participants reach a coherent collective decision.Funded by Collectiveware TIN2015-66863-C2-1-R (MINECO/FEDER) and 2014 SGR 118.Peer reviewe