MUC-4 Revisited: Document-level Event Analysis beyond Span-based Arguments

Helene Bøsei Olsen, Erik Velldal, Lilja Øvrelid


Abstract
Automatically predicting structured representations of events has long been a central goal in information extraction, yet most contemporary work remains limited to identifying contiguous text spans as event arguments. This span-centric formulation fails to capture higher-level aspects of real-world events, such as actor identities, temporal scope, and aggregated outcomes, that many event-centred applications depend on. While commonly treated as a standard extractive benchmark, MUC-4 originally combined span-based arguments with normalised, inferred, and categorical fields, reflecting a richer, application-driven design. In this paper, we revisit MUC-4 in its full original formulation, casting it as an abstractive event analysis task that connect traditional event extraction goals with modern generative and document-level paradigms. We provide the first systematic evaluation of fine-tuned generative models in this extended formulation on MUC-4, examining how post-training stages and model size affect performance across both span-based and higher-level, semantically grounded event information. An extensive error analysis highlights practical challenges and directions for future work.
Anthology ID:
2026.lrec-main.617
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:
7766–7780
Language:
URL:
https://preview.aclanthology.org/ingest-lrec/2026.lrec-main.617/
DOI:
Bibkey:
Cite (ACL):
Helene Bøsei Olsen, Erik Velldal, and Lilja Øvrelid. 2026. MUC-4 Revisited: Document-level Event Analysis beyond Span-based Arguments. International Conference on Language Resources and Evaluation, main:7766–7780.
Cite (Informal):
MUC-4 Revisited: Document-level Event Analysis beyond Span-based Arguments (Olsen et al., LREC 2026)
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PDF:
https://preview.aclanthology.org/ingest-lrec/2026.lrec-main.617.pdf