Arguments do not live in isolation and are linked to
each other by various types of relations: the relation-
al layer deals with identifying and formally repre-
senting them, in view of their use in other layers or
even for descriptive and presentation purposes, since
they are essential for an understanding of what is
actually going on in an argumentation process.
Examples of important relationships are ( 1) the sub-
argument and superargument relationships, indicat-
ing how an argument is built incrementally on top of
other arguments; ( 2) the attack relationship, indicat-
ing that an argument is incompatible with another
argument in some sense, for example, because they
have contradictory claims, or one claim contradicts
some premise or assumption on which the other is
based; ( 3) the support relationship, intuitively mean-
ing that an argument provides some backing to
another, and admitting several, even rather dissimi-
lar, interpretations, depending on the actual nature
of this backing; ( 4) a preference relationship, ranking
arguments according to some criterion, and admit-
ting again a variety of instantiations ranging from
strength to credibility to value-based evaluations.
What relationships are significant and how to
identify them are highly context-dependent matters.
Note in particular that identifying argument relations may be an easy mechanical procedure in settings where arguments are formally built from a
knowledge base, while in an argument mining scenario it is a task as challenging as the identification
of the arguments themselves.
This layer deals with the exchange of arguments
among different agents (or even between an agent
and itself, in a scenario where argumentative reasoning is conceived as a monological activity) according
to formal dialogue rules. Agents may engage in the
exchange of arguments for a variety of purposes with
several dialogue types having been identified in the
literature, like inquiry, negotiation, information-seeking, deliberation, and persuasion. In all cases the
exchange can be formalized as a dialogue game,
which is normally made up of a set of communicative acts called moves, and a protocol specifying
Figure 1. Key Aspects of Argumentation.
Structural layer: How are arguments constructed?
Relational layer: What are the relationships between arguments?
Dialogical layer: How can argumentation be
undertaken in dialogues?
Assessment layer: How can a constellation of interacting arguments
be evaluated and conclusions drawn?
Rhetorical layer: How can argumentation be tailored for an
audience so that it is persuasive?