About the Project This PhD project aims to develop personalised conversational systems by leveraging user simulation, supported by recent advancements in large language models with their strong capability in natural language understanding and generation. Conversational systems or dialogue systems are useful in supporting interactive information exchanging, especially between human and machines. Conventional approaches rely on the optimisation of key components, which put high weights on human-labelled data and commonly limited in domain scope and prone to various data collection biases. To mitigate these limitations, this PhD project aims to develop user simulators, capable of accurately imitating interactions between real users and systems. By varying the personality of simulated users, reliable training input can be obtained for developing conversational systems. Furthermore, the use of LLMs can further enhance the potential of user simulators in modelling natural languages. This PhD project is part of an ongoing collaboration with researchers from UCL and the University of Edinburgh. For additional information, please contact Dr Xi Wang at xi.wangsheffield.ac.uk. When reaching out, kindly use the subject line '[PhD-Sim4Conv] - [Your Name] - [Your Current Institution] - [Your Country]'. Supervisor Bio Dr Xi Wang is a Lecturer in Natural Language Processing at the Department of Computer Science, the University of Sheffield, with his research interests in Conversational AI, personalisation, retrieval augmented generation, as well as relevant topics among NLP and IR. About the Department/Research Group 99 percent of our research is rated in the highest two categories in the REF 2021, meaning it is classed as world-leading or internationally excellent. We are rated as 8th nationally for the quality of our research environment, showing that the Department of Computer Science is a vibrant and progressive place to undertake research. The successful candidate will join the Natural Language Processing group, one of the largest and most successful language processing groups in the UK and has a strong global reputation. Candidate Requirements Minimum 2.1 bachelor’s degree or master’s degree in a relevant discipline (e.g., artificial intelligence, computer science and data science) or its international equivalent to provide evidence for sufficient computing and mathematical background. Solid programming experience and familiarity with deep learning environments (e.g., PyTorch). Passionate and self-motivated about conducting high quality research in NLP with a special focus on the topic of advanced conversational systems. If English is not your first language, you must have an IELTS score of 6.5 overall, with no less than 6.0 in each component. How to Apply To apply for a PhD studentship, applications must be made directly to the University of Sheffield using the Postgraduate Online Application Form. Make sure you name Dr Xi Wang as your proposed supervisor(s). Information on what documents are required and a link to the application form can be found here - https://www.sheffield.ac.uk/postgraduate/phd/apply/applying The form has comprehensive instructions for you to follow, and pop-up help is available. Funding Notes The PhD studentship will cover standard UK home tuition fees and provide a tax-free stipend at the standard UK Research Council rate (currently £19,237 for the 2024/25 academic year) for 3.5 years. If you are an overseas student, you are eligible to apply but you must have the means to pay the difference between the UK and overseas tuition fees by securing additional funding or self-funding. Further information on International fees can be found here: https://www.sheffield.ac.uk/new-students/tuition-fees/fees-lookup £18,622 for 2023/24