From Noise to Signal: When Outliers Seed New Topics

Evangelia Zve, Gauvain Bourgne, Benjamin Icard, Jean-Gabriel Ganascia


Abstract
Outliers in dynamic topic modeling are typically treated as noise, yet we show that some can serve as early signals of emerging topics. We introduce a temporal taxonomy of news-document trajectories that defines how documents relate to topic formation over time. It distinguishes anticipatory outliers, which precede the topics they later join, from documents that either reinforce existing topics or remain isolated. By capturing these trajectories, the taxonomy links weak-signal detection with temporal topic modeling and clarifies how individual articles anticipate, initiate, or drift within evolving clusters. We implement it in a cumulative clustering setting using document embeddings from eleven state-of-the-art language models and evaluate it retrospectively on HydroNewsFr, a French news corpus on the hydrogen economy. Inter-model agreement reveals a small, high-consensus subset of anticipatory outliers, increasing confidence in these labels. Qualitative case studies further illustrate these trajectories through concrete topic developments.
Anthology ID:
2026.lrec-1.596
Original:
2026.lrec-1.596v1
Version 2:
2026.lrec-1.596v2
Volume:
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
Stelios Piperidis, Núria Bel, Henk van den Heuvel, Nancy Ide, Simon Krek, Antonio Toral
Venue:
LREC
SIG:
Publisher:
ELRA Language Resource Association
Note:
Pages:
7523–7533
Language:
URL:
https://aclanthology.org/2026.lrec-1.596/
DOI:
10.63317/5c6zvq4nbjdq
Bibkey:
Cite (ACL):
Evangelia Zve, Gauvain Bourgne, Benjamin Icard, and Jean-Gabriel Ganascia. 2026. From Noise to Signal: When Outliers Seed New Topics. In Proceedings of the Fifteenth Language Resources and Evaluation Conference, pages 7523–7533, Palma de Mallorca, Spain. ELRA Language Resource Association.
Cite (Informal):
From Noise to Signal: When Outliers Seed New Topics (Zve et al., LREC 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.lrec-1.596.pdf
External:
 https://lrec.elra.info/lrec2026-main-596