@inproceedings{nagasawa-etal-2026-tree,
    title = "Tree-Based Interview Topic Guidance for Collecting Target Information under Adaptive Topic continuation/switching",
    author = "Nagasawa, Fuminori  and
      Hashimoto, Ekai  and
      Shiramatsu, Shun",
    editor = "Choi, Jinho D.  and
      Chen, Yun-Nung  and
      Funakoshi, Kotaro  and
      Emami, Ali",
    booktitle = "Proceedings of the 27th Annual Meeting of the Special Interest Group on Discourse and Dialogue",
    month = aug,
    year = "2026",
    address = "Atlanta, Georgia, USA",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/ingest-nlpsi/2026.sigdial-1.35/",
    pages = "497--515",
    abstract = "Interview-style dialogue for service recommendation must both elicit users' underlying needs and collect information required for recommendation. We propose a Question Tree{--}based guidance method that steers dialogue toward target information while allowing externally controlled topic continuation and switching. The Question Tree represents questions as nodes linked by parent{--}child derivational relations. For each user response, the system generates deepening and target-approaching question candidates, appends suitable candidates to the tree, and selects the next question from child or sibling nodes according to the required topic-control action. Selection uses a weighted combination of sentence-embedding similarity to the current dialogue context and to the target information. We evaluated the method in LLM-based dialogue simulations with externally controlled continuation and switching. The combined method increased the mean target-information collection rate from 10.8{\%} to 26.6{\%} after 10 turns and reduced cross-session variability, without a statistically significant difference from the baseline in the limited human naturalness evaluation. These results indicate that explicit tree-based topic guidance can support information collection when combined with external topic-adaptation modules."
}