Abstract
This thesis provides a formal treatment of the utilisation of enthymemes indialogical settings, and thus contributes to the formalisation of a key argumentative
practice ubiquitous in real world dialogues.
The underlying argumentation formalism of our work is ASPIC+, a general
framework for structured argumentation which is shown to capture existing
systems for argumentation based reasoning. Due to ASPIC+’s lack of support
for enthymemes, we modify the ASPIC+ framework so as to enable representation
of a broad range of argumentative structures, including arguments and
enthymemes. We formalise how an agent i can utilise its model of another
agent j’s beliefs and arguments, in order to construct enthymemes from its
arguments to send to j, while attempting to ensure that j is capable of reconstructing
the original arguments from their respective enthymemes. We
then formally define the process of reconstructing the argument from which a
received enthymeme was originally constructed, similarly using agents’ models
of each others’ beliefs and arguments.
We define mechanisms for constructing and maintaining an agent’s model of
another agent’s beliefs and arguments. The mechanisms are based on agents’
dialogical exchanges, as well as their quantitatively measured like-mindedness.
The latter harnesses the notion that agents in the environment are distributed
in groups and communities that are formed on the basis of agents’ intrinsic
and extrinsic properties.
We then present a general framework for argumentation based dialogue. The
framework formalises core elements that are common amongst existing dialogue
systems while abstracting away from the details that restricts it to
particular systems or specific dialogue types. To illustrate its generality, the
framework is instantiated to capture existing dialogue systems, each for a
different dialogue type.
The framework is then instantiated to represent a system for a new dialogue
type, called resolution. Resolution dialogues are designed to be easily embedded
within other dialogues of potentially differing types, and enable their resolution dialogues can additionally capture and generalise one of the primary
dialogical mechanisms in existing dialogue systems, and can formalise
information-seeking and potentially inquiry dialogues. We then show that
resolution dialogues can additionally capture and generalise one of the primary
dialogical mechanisms in existing dialogue systems, and can formalise
information-seeking and potentially inquiry dialogues.
| Date of Award | 2017 |
|---|---|
| Original language | English |
| Awarding Institution |
|
| Supervisor | Sanjay Modgil (Supervisor) & Odinaldo Rodrigues (Supervisor) |