Continuous Difficulty Control for Text Simplification

Yuki Fujiwara, Rina Miyata, Tomoyuki Kajiwara, Yuki Arase


Abstract
Controlling text difficulty is crucial for adapting texts to individual language learners. Existing controllable text simplification methods condition generation on discrete proficiency-level tokens, treating these levels as independent categories. As a result, they fail to capture the ordinal structure of language proficiency and cannot provide fine-grained control beyond predefined levels. To address this limitation, we propose a continuous difficulty control method that adjusts simplification difficulty by editing the norm of a conditioning embedding derived from the input sentence semantics. The embedding is incorporated into the transformer decoder through attention-based conditioning, enabling continuous control over output difficulty while modeling ordinal relationships across levels. Unlike token-based approaches, our method supports interpolation between proficiency levels and flexible control over edit magnitude. Experiments on controllable text simplification benchmarks demonstrate improved difficulty controllability, simplification quality, and sentence difficulty estimation performance.
Anthology ID:
2026.findings-emnlp.677
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
14216–14227
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.677/
DOI:
Bibkey:
Cite (ACL):
Yuki Fujiwara, Rina Miyata, Tomoyuki Kajiwara, and Yuki Arase. 2026. Continuous Difficulty Control for Text Simplification. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 14216–14227, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Continuous Difficulty Control for Text Simplification (Fujiwara et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.677.pdf