Nicholas Thomas Walker


2025

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A Voice-Controlled Dialogue System for NPC Interaction using Large Language Models
Milan Wevelsiep | Nicholas Thomas Walker | Nicolas Wagner | Stefan Ultes
Proceedings of the 15th International Workshop on Spoken Dialogue Systems Technology

This paper explores the integration of voice-controlled dialogue systems in narrative-driven video games, addressing the limitations of existing approaches. We propose a hybrid interface that allows players to freely paraphrase predefined dialogue options, combining player expressiveness with narrative cohesion. The prototype was developed in Unity, and a large language model was used to map the transcribed voice input to existing dialogue options. The approach was evaluated in a user study (n=14) that compared the hybrid interface to traditional point-and-click methods. Results indicate the proposed interface enhances player’s degree of joy and perceived freedom while maintaining narrative consistency. The findings provide insights into the design of scalable and engaging voice-controlled systems for interactive storytelling. Future research should focus on reducing latency and refining language model accuracy to further improve user experience and immersion.

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Retrieving Relevant Knowledge Subgraphs for Task-Oriented Dialogue
Nicholas Thomas Walker | Pierre Lison | Laetitia Hilgendorf | Nicolas Wagner | Stefan Ultes
Proceedings of the 26th Annual Meeting of the Special Interest Group on Discourse and Dialogue

In this paper, we present an approach for extracting knowledge graph information for retrieval augmented generation in dialogue systems. Knowledge graphs are a rich source of background information, but the inclusion of more potentially useful information in a system prompt risks decreased model performance from excess context. We investigate a method of retrieving relevant subgraphs of maximum relevance and minimum size by framing this trade-off as a Prize-collecting Steiner Tree problem. The results of our user study and analysis indicate promising efficacy of a simple subgraph retrieval approach compared with a top-K retrieval model.

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Knowledge Graphs and Representational Models for Dialogue Systems
Nicholas Thomas Walker
Proceedings of the 21st Workshop of Young Researchers' Roundtable on Spoken Dialogue Systems

I am interested graph-based dialogue management for dialogue systems, specifically the use of knowledge- graphs. Representations of knowledge combining in- formation about the world with dialogue or user-specific information, such as personal knowledge graphs (Balog and Kenter, 2019) are of particular interest to me. Knowl- edge graphs have the flexibility to represent diverse in- formation such as dialogue specific information, gen- eral world knowledge, and even situated knowledge in the case of embodied dialogue systems. Much of my previous work has investigated knowledge graphs in an HRI context that combined these attributes (Walker et al., 2022b).

2024

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Dialogue Management with Graph-structured Knowledge
Nicholas Thomas Walker
Proceedings of the 20th Workshop of Young Researchers' Roundtable on Spoken Dialogue Systems

I am a postdoctoral researcher at Otto-Friedrich University of Bamberg, and my research interests include the knowledge-grounded dialogue systems, logical rule-based reasoning for dialogue management, and human-robot interaction.