An essential step to evaluating arguments is moving from the weight of individual premises to the weight of the conclusion. In order to perform this step, one must understand the relationship between the premises in the argument. In the past, analyzing premise relations in informal logic has been limited primarily to the linked-convergent distinction. This distinction has failed to resolve some of the basic problems in finding a definition because it has underestimated the degree to which premises interact with each (...) other in some complicated way. Embracing concepts from holistic epistemology, I argue that evaluating a premise involves considering a wide set of presuppositions and implications that that premise, if accepted, carries. I call this wide set the premise/world. The relationship between premises is then essentially just the relationship between these two premise/worlds. (shrink)

In previous work I argued against (i) the likelihood of finding a theoretically sound foundation for the linked/convergent distinction and (ii) the utility of the distinction even if a sound theoretical basis could be found. Here I subject Douglas Walton’s comprehensive discussion of the linked/convergent distinction found in Argument Structure: A Pragmatic Theory to careful scrutiny and argue that at best Walton’s theory remains incomplete and that attempts to fill out the details will run afoul of at least one of (...) the problems adduced above—i.e., result in either a theoretically unsound distinction or a theoretically sound, but unnecessary distinction. (shrink)

Quantitative apparatus for assessing strength of an argument was improved in the article. A probative generalisation and verification of the R.Yanal's algorithm to calculate convergent argument were proposed. The generalization obtained deals with both quantity (or number) and quality (or truth-values) of the argument's reasons.

In this paper, a survey is presented of the main approaches to the structure of argumentation. The paper starts with a historical overview of the distinctions between various types of argument structure. Next, the main definitions given in the various approaches are discussed as well as the methods that are proposed to deal with doubtful cases.

An approach to argument macrostructure -- The dialectical nature of argument -- Toulmin's problematic notion of warrant -- The linked-convergent distinction, a first approximation -- Argument structure and disciplinary perspective : the linked-convergent versus multiple-co-ordinatively compound distinctions -- The linked-convergent distinction, refining the criterion -- Argument structure and enthymemes -- From analysis to evaluation.

In this paper, it is explained that a dialogical approach to complex argumentation can be fruitful for solving two important problems concerning the analysis of the argumentation structure. First, such an approach makes it possible to clarify the distinction between coordinative and multiple argumentation structures, and to identify clues in the presentation for each of these structures. Second, a dialogical approach can provide a basis for dealing more adequately with refutations of counterarguments.

One popular test for distinguishing linked and convergent argument structures is Robert Yanal's Ordinary Summing Test. Douglas Walton, in his comprehensive survey of possible candidates for the linked/convergent distinction, advocates a particular version of Yanal's test. In a recent article, Alexander Tyaglo proposes to generalize and verifY Yanal's algorithm for convergent arguments, the basis for Yanal's Ordinary Summing Test. In this paper I will argue that Yanal's ordinary summing equation does not demarcate convergence and so his Ordinary Summing Test fails. (...) Hence, despite Walton's recommendation or Tyaglo's generalization, the Ordinary Summing Test should not be used for distinguishing linked argument structures from convergent argument structures. (shrink)

Bayesian networks (BN) and argumentation diagrams (AD) are two predominant approaches to legal evidential reasoning, that are often treated as alternatives to one another. This paper argues that they are, instead, complimentary and proposes the beginnings of a method to employ them in such a manner. The Bayesian approach tends to be used as a means to analyse the findings of forensic scientists. As such, it constitutes a means to perform evidential reasoning. The design of Bayesian networks that accurately and (...) comprehensively represent the relationships between investigative hypotheses and evidence remains difficult and sometimes contentious, however. Argumentation diagrams are representations of reasoning, and are used as a means to scrutinise reasoning (among other applications). In evidential reasoning, they tend to be used to represent and scrutinise the way humans reason about evidence. This paper examines how argumentation diagrams can be used to scrutinise Bayesian evidential reasoning by developing a method to extract argument diagrams from BN. (shrink)

Toward a Shared Metaphoric Meaning in Children's Discourse: The Role of Argumentation The text deals with the phenomenon of understanding and interpreting metaphoric expressions in children. Of the many metaphoric figures, one type was selected: the ‘so-called’ psychological-physical metaphors that illuminate a psychological experience by appealing to an event in the physical domain. The data consist of children's discussions in pairs, in which they make a joint interpretation of metaphors including a dual-function adjective, e.g., a hard person, a sweet person, (...) an empty person. A hundred and forty-four dialogues between peer dyads were recorded from three age groups : 6;6-7;6, 8;6-9;6, and 10;6-11;6. The children's task was to prepare an interpretation of metaphorical expressions for two television quiz shows, one for peers and one for young preschoolers. The research design was balanced for age, gender, and order of metaphoric interpretation in the two experimental variants. Following Quignard's model, we analyzed children's argumentation as a particular case of dialogical problem solving, whereby children had to understand the metaphoric meaning and convey it to the potential addressee. The results show an interesting dynamic in the argumentative orientation of the pro and the contra type, depending on the age of interlocutors. The frequency of metaphoric interpretations in opposition to those presented by the partner decreases with the children's age, but the frequency of compound proposals with the use of the partner's contribution increases. For the younger addressee, children most frequently interpret metaphors as descriptions of magical situations. (shrink)