Explainable Rankings through Computational Argumentation

About the Project

Project Description

Ranking systems are central to decision-making in domains such as sports analytics, search engines, recruitment, and academic evaluations. Yet, most ranking algorithms operate as opaque black boxes, providing little insight into why one item is ranked above another. This PhD project aims to develop explainable ranking systems that compute rankings from incomplete comparison data and provide interactive explanations that justify these rankings.

The core innovation lies in applying computational argumentation theory, a formal framework for modelling arguments, counterarguments, and attack relations, to ranking problems. This approach will enable systems to defend their decisions in dialogue with users, offering transparency and trustworthiness. Two key research questions will guide the work:

1. Can existing ranking methods be reformulated within an argumentation-theoretic framework?
2. Can entirely new ranking methods be designed using argumentation principles?

While the primary focus will be on formal argumentation, the project will also explore how Large Language Models (LLMs) can enhance user interaction by generating natural, context-aware explanations and supporting dialogue. LLMs will serve as a bridge between formal reasoning and human-understandable communication, making the system more accessible and engaging.

Sports analytics, rich in comparison data and public discourse, will serve as a primary testbed, though applications extend to search engines, recruitment, and decision-support systems.

Aims:

• Develop an argumentation-based framework for explainable rankings.
• Create interactive systems capable of defending ranking decisions through dialogue.
• Investigate the role of LLMs in improving explanation quality and user experience.

Methods:

• Formal modelling of arguments and attack relations for ranking problems.
• Algorithm design for ranking generation and argument evaluation.
• Integration of LLMs for natural, context-aware explanations.
• Empirical evaluation using sports and other real-world datasets.

Deliverables:

• A formal argumentation-based language for ranking explanations.
• Prototype system combining ranking algorithms with interactive dialogue.
• Comparative study of argumentation-based vs. traditional ranking methods.
• Publications in AI, computational linguistics and decision-support venues.

Keywords:

Explainable AI, Computational Argumentation, Ranking Algorithms, Large Language Models, Dialogue Systems, Decision Support.

How to Apply

This project is accepting applications all year round, for self-funded candidates.

Mode of Study: Full-time or part-time

Please submit your application via Computer Science and Informatics - Study - Cardiff University

In the funding field of your application, indicate “I am applying for a self-funded PhD in Computer Science and Informatics”, and specify the project title and supervisors of this project in the text box provided.

Academic criteria: A 2:1 Honours undergraduate degree or a master's degree, in computing or a related subject. Applicants with appropriate professional experience are also considered. Degree-level mathematics (or equivalent) is required for research in some project areas.

Applicants must demonstrate English language proficiency. Students who do not have English as a first language must prove this by obtaining an IELTS score of at least 6.5 overall, with a minimum of 6.0 in each skills component. A full list of accepted qualifications is available here: https://www.cardiff.ac.uk/study/international/english-language-requirements/postgraduate

If you are interested, please contact Dr Richard Booth (boothr2@cardiff.ac.uk) sending your CV in the first instance. The application process requires you to develop an individual research proposal jointly with the supervision team, which builds on the information provided in this advert.

Once you have developed the proposal with support from the supervisors, please submit your application following the instructions provided below.

Please submit your application via Computer Science and Informatics - Study - Cardiff University

In order to be considered candidates must submit the following information:

• In the ‘Research Proposal’ section of the application enter the name of the project you are applying to and upload your Individual research proposal. Your research proposal should not exceed 2000 words, including references and bibliography.
• A personal statement (as part of the university application form, or as a separate attachment, if you prefer).
• A CV. Guidance on CVs for a PhD position can be found on the FindAPhD website.
• Qualification certificates and Transcripts - original and English translation, if applicable.
• References x 2 which should be academic references. Please note you need to provide the reference documents as part of your application.
• Proof of English language (if applicable).

Interview– If the application meets all of the entrance requirements listed above, you will be invited to an interview.

Funding Notes

This project is offered for self-funded students only, or those with their own sponsorship or scholarship award. Where applicable, candidates will be required to cover the cost of a student visa, the healthcare surcharge, and any other costs of moving to the UK to study. These costs will not be covered by the School of Computer Science and Informatics.