A dialogical model of case law dynamics

We describe a set of dialogue moves which give a procedure to model the development of case law over a sequence of cases

Explaining legal decisions using IRAC

We suggest that the Issue, Rule, Application, Conclusion (IRAC) method can be used to produce a natural explanation of legal case outcomes. We show how a current methodology for representing knowledge of legal cases can be used to provide such explanations

An explainable approach to deducing outcomes in european court of human rights cases using ADFs

In this paper we present an argumentation-based approach to representing and reasoning about a domain of law that has previously been addressed through a machine learning approach. The domain concerns cases that all fall within the remit of a specific Article within the European Court of Human Rights. We perform a comparison between the approaches, based on two criteria: ability of the model to accurately replicate the decision that was made in the real life legal cases within the particular domain, and the quality of the explanation provided by the models. Our initial results show that the system based on the argumentation approach improves on the machine learning results in terms of accuracy, and can explain its outcomes in terms of the issue on which the case turned, and the factors that were crucial in arriving at the conclusion

Dimensions and values for legal CBR

We build on two recent attempts to formalise reasoning with dimensions which effectively map dimensions into factors. These enable propositional reasoning, but sometimes a balance between dimensions needs to be struck, and to permit trade offs we need to keep the magnitudes and so reason more geometrically. We discuss dimensions and values, arguing that values can play several distinct roles, both explaining preferences between factors and indicating the purposes of the law

Value-based argumentation

Value-based argumentation is concerned with recognising, accounting for, and reasoning with, the social purposes promoted by agents’ beliefs and actions. Value-based argumentation frameworks extend Dung’s abstract argumentation frameworks by ascribing an additional property to arguments, representing the values they promote, and recognising audiences. Values are ordered according to the preferences of an audience (different audiences will have different preferences) and an attack is successful only if the value of the attacked argument is not preferred to its attacker by its audience. Arguments can be related to values through the use of an argumentation scheme, thus enabling us to structure value-based argumentation. We describe the motivation of valuebased argumentation, its formal description and properties, the argumentation scheme and its associated critical questions and some of the applications to which value-based argumentation has been put

Empty names

Empty names are names which do not refer to anything. Apparently empty names are used in many different ways, and an analysis which looks good for one kind of use can look bad for another. I aim to get a wide enough angle on the issues that the solutions I propose won’t run into that problem. Chapter one is about names which are empty because they were introduced in the context of mistakes and lies. I see how we can assign truth values to utterances containing such names. I also look at how genuinely empty names could be meaningful at all, and examine how they could fit into a Davidsonian theory of meaning. Chapter two is about mental states corresponding to the names dealt with in chapter one. I try to give an account of how beliefs could be subject to rational norms without appealing to their propositional contents. I do this by showing that puzzles about co-referring names can motivate such an account independently, and that the empty name beliefs can fit into this framework easily. Chapter three is about attitude ascriptions and propositions. I consider different ways of responding to the problem of having propositions but no objects for the propositions to be about. I defend an account involving gappy Fregean propositions, and give a semantics for attitude ascriptions which incorporates them. Chapter four is about the names that occur in fiction. I argue that we should take these to be polysemous between a use referring to an artistic creation and a use primarily suited to pretence. For the first use, I survey proposals for ontologies of fictional characters, and suggest one of my own. To make sense of the second use, I use a two- dimensional semantics, which also helps with the problem of negative existentials

Argument Schemes for Reasoning About the Actions of Others

In practical reasoning, it is important to take into consideration what other agents will do, since this will often influence the effect of actions performed by the agent concerned. In previous treatments, the actions of others must either be assumed, or argued for using a similar form of practical reasoning. Such arguments, however, will also depend on assumptions about the beliefs, values and preferences of the other agents, and so are difficult to justify. In this paper we capture, in the form of argumentation schemes, reasoning about what others will do, which depends not on assuming particular actions, but through consideration of the expected utility (based on the promotion and demotion of values) of particular actions and alternatives. Such arguments depend only on the values and preferences of the agent concerned, and do not require assumptions about the beliefs, values and preferences of the other relevant agents. We illustrate the approach with a running example based on Prisoner’s Dilemma

Lessons rom implementing factors with magnitude

We discuss the lessons learned from implementing a CATO style system using factors with magnitude. In particular we identify that giving factors magnitudes enables a diversity of reasoning styles and arguments. We distinguish a variety of ways in which factors combine to determine abstract factors. We discuss several different roles for values. Finally we identify the additional value related information required to produce a working program: thresholds and weights as well as a simple preference ordering

Relating the ANGELIC methodology and ASPIC+

We relate the ANGELIC methodology for acquiring and encapsulating domain knowledge to the ASPIC+ framework for structured argumentation. In so doing we hope to facilitate the building of applications in concrete domains by linking a successful methodology to a proven theoretical framework. We use an example from the ASPIC+ literature to illustrate the relationship