Acceptable Arguments Research Articles

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Abstract argumentation frameworks introduced by Dung [Dun95] are a formal way of representing discussions de ned through arguments and a binary attack relation between them. In dynamic settings there is a need to allow for uncertainty in such argumentation frameworks, hence attack-incomplete and argument-incomplete argumentation frameworks are considered as well. Different semantics are de ned in order to identify a set of acceptable arguments, and the verification problem asks whether some given set is an extension for a given semantics. This survey gives an overview of the complexity of the verification problem for different semantics in complete and incomplete argumentation frameworks.

Complexity Results and Algorithms for Extension Enforcement in Abstract Argumentation

Argumentation is an active area of modern artificial intelligence (AI) research, with connections to a range of fields, from computational complexity theory and knowledge representation and reasoning to philosophy and social sciences, as well as application-oriented work in domains such as legal reasoning, multi-agent systems, and decision support. Argumentation frameworks (AFs) of abstract argumentation have become the graph-based formal model of choice for many approaches to argumentation in AI, with semantics defining sets of jointly acceptable arguments, i.e., extensions. Understanding the dynamics of AFs has been recently recognized as an important topic in the study of argumentation in AI. In this work, we focus on the so-called extension enforcement problem in abstract argumentation as a recently proposed form of argumentation dynamics. We provide a nearly complete computational complexity map of argument-fixed extension enforcement under various major AF semantics, with results ranging from polynomial-time algorithms to completeness for the second level of the polynomial hierarchy. Complementing the complexity results, we propose algorithms for NP-hard extension enforcement based on constraint optimization under the maximum satisfiability (MaxSAT) paradigm. Going beyond NP, we propose novel MaxSAT-based counterexample-guided abstraction refinement procedures for the second-level complete problems and present empirical results on a prototype system constituting the first approach to extension enforcement in its generality.

Bipolarity in temporal argumentation frameworks

A Timed Argumentation Framework (TAF) is a formalism where arguments are only valid for consideration during specific intervals of time, called availability intervals, which are defined for every individual argument. The original proposal is based on a single abstract notion of attack between arguments that remains static and permanent in time. Thus, in general, when identifying the set of acceptable arguments, the outcome associated with a TAF will vary over time.Here, we are introducing an extension of TAF adding the capability of modeling a support relation between arguments. In this sense, the resulting framework provides a suitable model for different time-dependent issues; thus, the main contribution of this work is to provide an enhanced framework for modeling a positive (support) and negative (attack) interaction which varies over time, features that are highly relevant in many real-world situations. This addition leads to a Timed Bipolar Argumentation Framework (T-BAF), where classical argument extensions can be defined, aiming at advancing in the integration of temporal argumentation in different application domains.

An approach to characterize graded entailment of arguments through a label-based framework

Argumentation theory is a powerful paradigm that formalizes a type of commonsense reasoning that aims to simulate the human ability to resolve a specific problem in an intelligent manner. A classical argumentation process takes into account only the properties related to the intrinsic logical soundness of an argument in order to determine its acceptability status. However, these properties are not always the only ones that matter to establish the argument's acceptability—there exist other qualities, such as strength, weight, social votes, trust degree, relevance level, and certainty degree, among others.In this work, we redefine the argumentative process to improve the analysis of arguments by considering their special features in order to obtain more refined results. Towards this end, we propose adding meta-level information to the arguments in the form of labels representing quantifiable data ranking over a range of fuzzy valuations. These labels are propagated through an argumentative graph according to the relations of support, conflict, and aggregation between arguments. Through this process we obtain final labels that are useful in determining argument acceptability.

Legitimizing Corporate (Un) Sustainability: A Case Study of Passive SMEs

The objective of this article is to explore how decision makers in small- and medium-sized enterprises explain their lack of commitment to sustainability through various justifications. These justifications are intended to rationalize and legitimize, through socially acceptable arguments, the absence of substantial actions in this area. A case study based on 33 interviews in nine Canadian small- and medium-sized enterprises showed that managers rationalize their lack of commitment to sustainability in several different ways. These can be grouped into three main types of justifications: prioritization of economic survival, looking for a scapegoat, and denial and minimization (denial of negative impacts, minimization of sustainability issues, self-proclaimed sustainability). The study contributes to bridge the gap between the literatures on neutralization theory, resistance to institutional pressures, and corporate unsustainability. It also sheds further light on the reasons underlying the lack of commitment to sustainable development and how managers justify this to themselves and others.

Looking-ahead in backtracking algorithms for abstract argumentation

We refine implemented backtracking algorithms for a number of problems related to Dung's argumentation frameworks. Under admissible, preferred, complete, stable, semi stable, and ideal semantics we add enhancements, what are so-called global looking-ahead pruning strategies, to the-state-of-the-art implementations of two problems. First, we tackle the extension enumeration problem: constructing some/all set(s) of acceptable arguments of a given argumentation framework. Second, we address the acceptance decision problem: deciding whether an argument is in some/all set(s) of accepted arguments of a given argumentation framework. The experiments that we report show that the speedup gain of the new enhancements is quite significant.

How Do Learners Conceptualize Plane Mirror Reflection? A Case Study of Grade 11 South African Learners

The focus of this paper is to understand how Grade 11 learners conceptualize image formation in a plane mirror. The sample consisted of 70 learners, selected by using the convenient sampling technique, from a selected urban senior secondary school in the Province of the Eastern Cape in South Africa. The mixed-method nature of the research design was accompanied by the use of the 4-Tier Optics Diagnostic Instrument (4ODI), which enabled the collection of both quantitative and qualitative data simultaneously. The findings emerged from the analysis of seven relevant questions of the 4ODI, which indicated that the learners had held four types of conceptions, that is, scientifically-accepted strong conceptions, scientifically-accepted weak conceptions, alternative conceptions, and errors due to lack of knowledge. It also emerged from this study that not all the correct responses of the participants could be justified by scientifically acceptable arguments.

Politics of Science: Unwarranted Encounters.

This communication highlights a very pertinent and recent case of an erroneous representation of the Indian borders in an article 'India by the numbers' by Richard Van Noorden in Nature ( http://www.nature.com/news/india-by-the-numbers-1.17519 ) where a considerable part of the Jammu and Kashmir State of India is missing in the map incorporated in the article. The article received a series of comments showing disappointment on the issue and a need for the correction to the depicted Indian borders. The editor instead of making corrections to the map has issued a statement that 'the map shows land areas currently administered by the Indian Government', that in no way can be considered as an acceptable argument. We wish the focus of this well written article had remained on science rather than introducing unnecessary controversies.

Combining conceptual graphs and argumentation for aiding in the teleexpertise

Current medical information systems are too complex to be meaningfully exploited. Hence there is a need to develop new strategies for maximising the exploitation of medical data to the benefit of medical professionals. It is against this backdrop that we want to propose a tangible contribution by providing a tool which combines conceptual graphs and Dung׳s argumentation system in order to assist medical professionals in their decision making process. The proposed tool allows medical professionals to easily manipulate and visualise queries and answers for making decisions during the practice of teleexpertise. The knowledge modelling is made using an open application programming interface (API) called CoGui, which offers the means for building structured knowledge bases with the dedicated functionalities of graph-based reasoning via retrieved data from different institutions (hospitals, national security centre, and nursing homes). The tool that we have described in this study supports a formal traceable structure of the reasoning with acceptable arguments to elucidate some ethical problems that occur very often in the telemedicine domain.

On Computing Explanations in Argumentation

Argumentation can be viewed as a process of generating explanations. However, existing argumentation semantics are developed for identifying acceptable arguments within a set, rather than giving concrete justifications for them. In this work, we propose a new argumentation semantics, related admissibility, designed for giving explanations to arguments in both Abstract Argumentation and Assumption-based Argumentation. We identify different types of explanations defined in terms of the new semantics. We also give a correct computational counterpart for explanations using dispute forests.

PLEA BARGAINING: A PANACEA TOWARDS PRISON DECONGESTION IN NIGERIA

Against the panoramic view of the criminal justice reform agenda in Nigeria, the plea bargaining procedure is yet to be fully recognized as a major intervention strategy to deal with the problems in the Nigerian criminal justice administration. This paper therefore conceptualized the concept of plea bargaining. The legal basis for plea, the justifications for plea as well as the merits and demerits of the plea are discussed. The paper also highlights the major problems afflicting criminal justice administration and examines the steps being taken to deal with the problems. The emphasis is on strengthening arguments for a mutual acceptance of plea bargaining as a credible exist strategy by both the state and an alleged offender. The way forward in form of recommendations for the expansion and institutionalization of the practice is also discussed.

Основні західні теорії юридичної аргументації

This article concerns the most influential Western theories of legal argumentation developed by Chaim Perelman, Stephen Toulmіn, Robert Alexy, Douglas Walton, Frans van Eemeren, Rob Grootendorst and their students. These modern theories of argumentation recognize as quite acceptable arguments ad hominem, which in traditional logic are considered as non-admissible. Recognition of correctness of arguments ad hominem requires multifactorial approach in argumentation theory, which in addition to purely logical and purely legal analysis includes philosophical, psychological, moral dimensions of argumentation.

Modeling time and valuation in structured argumentation frameworks

Temporal Argumentation Frameworks (TAF) represent a recent extension of Dung’s abstract argumentation frameworks that consider the temporal availability of arguments. In a TAF, arguments are valid during specific time intervals, called availability intervals, while the attack relation of the framework remains static and permanent in time; thus, in general, when identifying the set of acceptable arguments, the outcome associated with a TAF will vary in time. We introduce an extension of TAF, called Extended Temporal Argumentation Framework (E-TAF), adding the capability of modeling the temporal availability of attacks among arguments, thus modeling special features of arguments varying over time and the possibility that attacks are only available in a given time interval.E-TAF will be enriched by considering Structured Abstract Argumentation, using Dynamic Argumentation Frameworks. The resulting framework, E-TAF∗, provides a suitable model for different time-dependent issues satisfying properties and equivalence results that permit to contrast the expressivity of E-TAF and E-TAF∗ with argumentation based on abstract frameworks. Thus, the main contribution here is to provide an enhanced framework for modeling special features of argumentation varying over time, which are relevant in many real-world situations. The proposal aims at advancing in the integration of time and valuation in the context of argumentation systems as well.

Contemporary art and unconditionality: ‘the genus of art’ in the art criticism of Chiba Shigeo

This article examines art criticism of the 1980s that sought to address the context and continuity of postwar Japanese avant-garde art. The emphasis is placed on the notion of ‘the genus of art [rui to shite no bijutsu]’, which the art critic Chiba Shigeo discussed in his Gendai bijutsu itsudatsushi (1986). Chiba argued for an autonomous current of postwar Japanese art separate from Western art history but the argument has been largely overshadowed by his ostensible nihonjinron. The term ‘the genus of art’, therefore, has not yet received an adequate critical treatment. The article rephrases this notion as a call for a more inclusive definition of art designed to challenge the conditions that regulate non-Western art. Rather than simply being a nationalist polemic against Western art history from a marginalized place, Japan, ‘the genus of art’ was intended to revitalize and redefine the aims of the avant-garde within the context of ‘contemporary art’. By fleshing out the textual details of ‘the genus of art’ and situating the notion within a larger discourse that interrogated the semiotic role of ‘Japan’ in a global exhibition context, the study repositions Chiba's writing as a potential argument for unconditional acceptance, or unconditionality, as one important ethical contribution of contemporary art.

Algorithms for Argumentation Semantics: Labeling Attacks as a Generalization of Labeling Arguments

A Dung argumentation framework (AF) is a pair (A,R): A is a set of abstract arguments and R ⊆ A×A is a binary relation, so-called the attack relation, for capturing the conflicting arguments. Labeling based algorithms for enumerating extensions (i.e. sets of acceptable arguments) have been set out such that arguments (i.e. elements of A) are the only subject for labeling. In this paper we present implemented algorithms for listing extensions by labeling attacks (i.e. elements of R) along with arguments. Specifically, these algorithms are concerned with enumerating all extensions of an AF under a number of argumentation semantics: preferred, stable, complete, semi stable, stage, ideal and grounded. Our algorithms have impact, in particular, on enumerating extensions of AF-extended models that allow attacks on attacks. To demonstrate this impact, we instantiate our algorithms for an example of such models: namely argumentation frameworks with recursive attacks (AFRA), thereby we end up with unified algorithms that enumerate extensions of any AF/AFRA.

Algorithms for decision problems in argument systems under preferred semantics

For Dungʼs model of abstract argumentation under preferred semantics, argumentation frameworks may have several distinct preferred extensions: i.e., in informal terms, sets of acceptable arguments. Thus the acceptance problem (for a specific argument) can consider deciding whether an argument is in at least one such extensions (credulously accepted) or in all such extensions (skeptically accepted). We start by presenting a new algorithm that enumerates all preferred extensions. Following this we build algorithms that decide the acceptance problem without requiring explicit enumeration of all extensions. We analyze the performance of our algorithms by comparing these to existing ones, and present experimental evidence that the new algorithms are more efficient with respect to the expected running time. Moreover, we extend our techniques to solve decision problems in a widely studied development of Dungʼs model: namely value-based argumentation frameworks (vafs). In this regard, we examine analogous notions to the problem of enumerating preferred extensions and present algorithms that decide subjective, respectively objective, acceptance.

A logic of argumentation for specification and verification of abstract argumentation frameworks

In this paper, we propose a logic of argumentation for the specification and verification (LA4SV) of requirements on Dung's abstract argumentation frameworks. We distinguish three kinds of decision problems for argumentation verification, called extension verification, framework verification, and specification verification respectively. For example, given a political requirement like if the argument to increase taxes is accepted, then the argument to increase services must be accepted too, we can either verify an extension of acceptable arguments, or all extensions of an argumentation framework, or all extensions of all argumentation frameworks satisfying a framework specification. We introduce the logic of argumentation verification to specify such requirements, and we represent the three verification problems of argumentation as model checking and theorem proving properties of the logic. Moreover, we recast the logic of argumentation verification in a modal framework, in order to express multiple extensions, and properties like transitivity and reflexivity of the attack relation. Finally, we introduce a logic of meta-argumentation where abstract argumentation is used to reason about abstract argumentation itself. We define the logic of meta-argumentation using the fibring methodology in such a way to represent attack relations not only among arguments but also among attacks. We show how to use this logic to verify the requirements of argumentation frameworks where higher-order attacks are allowed [A preliminary version of the logic of argumentation compliance was called the logic of abstract argumentation (2005).]

Modelling defeasible and prioritized support in bipolar argumentation

Cayrol and Lagasquie-Schiex introduce bipolar argumentation frameworks by introducing a second relation on the arguments for representing the support among them. The main drawback of their approach is that they cannot encode defeasible support, for instance they cannot model an attack towards a support relation. In this paper, we introduce a way to model defeasible support in bipolar argumentation frameworks. We use the methodology of meta-argumentation in which Dung’s theory is used to reason about itself. Dung’s well-known admissibility semantics can be used on this meta-argumentation framework to compute the acceptable arguments, and all properties of Dung’s classical theory are preserved. Moreover, we show how different contexts can lead to the alternative strengthening of the support relation over the attack relation, and converse. Finally, we present two applications of our methodology for modeling support, the case of arguments provided with an internal structure and the case of abstract dialectical frameworks.

Use of Pharmacokinetic Data Below Lower Limit of Quantitation Values

In assessing the pharmacokinetics (PK) of therapeutic agents, studies are commonly performed to evaluate the ‘washout’ of the drugs and metabolites after single or multiple doses. The author is often frustrated when viewing reports and publications where the lower concentrations of drugs are absent and reported as Below the Limit of Quantitation (BLQ). Similar circumstances occur in pharmacodynamic (PD) studies where biomarkers are suppressed to very low, but meaningful, concentrations. When seeking these missing values, a common response is referral to the 2001 FDA Guidance on Bioanalytical Method Validation (1) and the later 2007 AAPS Workshop Report (2). The former advises that use of measurements below the LLOQ is “not recommended”. Thus such values are not usually provided. The author herein provides arguments for provision and acceptance of such data in many circumstances. While this issue has been addressed previously in somewhat similar vein (3), it seems appropriate to revisit at the present time in view of the persistence of this analytical dilemma and the advancement of pharmacometric concepts and methods for dealing with low exposure data.

Argument-based agreements in agent societies

In this paper, we present an abstract argumentation framework for the support of agreement processes in agent societies. It takes into account arguments, attacks among them, and the social context of the agents that put forward arguments. Then, we define the semantics of the framework, providing a mechanism to evaluate arguments in view of other arguments posed in the argumentation process. We also provide a translation of the framework into a neural network that computes the set of acceptable arguments and can be tuned to give more or less importance to argument attacks. Finally, the framework is illustrated with an example in a real domain of a water-rights transfer market.