Sentence-Level Foresight in Small Language Models: A Diagnostic Study of Learning Signals and Calibration

Ahmet Rıfat Öztürk, Yağız Ekrem Dalar, Nedim Mutlu Sezer, Feyzi Arda Salihoğlu, Ömer Faruk Aksoy


Abstract
Small language models provide useful diagnostic settings for studying which learning signals can be acquired under limited computation and whether those signals translate into observable behavior. We study whether a DistilGPT-2-scale autoregressive language model can learn a sentence-level future signal from next-sentence prediction and self-loop hard negatives. Across three seeds on both WikiText-103 and WritingPrompts, ForesightLM-v2 consistently learns positive held-out hard-negative separation, indicating that the auxiliary future signal is learnable. Generation experiments, however, reveal a calibration gap between representation learning and behavioral utility. Five-candidate reranking substantially improves several automatic diagnostics, but comparable gains are obtained with generic reranking, random and shuffled future-score controls, and a matched training-free base-model reranking baseline. On the fixed five-candidate pool, removing the learned future term changes only 2 of 120 selected continuations. These results show that a small autoregressive model can acquire a measurable sentence-level future representation, while most observed generation gains are explained by candidate selection rather than by the learned future term itself. ForesightLM-v2 therefore serves as a controlled case study of the distinction between learning an auxiliary signal and making that signal behaviorally effective.
Anthology ID:
2026.babylm-main.2
Volume:
Proceedings of the Second BabyLM Workshop
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Leshem Choshen, Ryan Cotterell, Mustafa Omer Gul, Jaap Jumelet, Tal Linzen, Aaron Mueller, Suchir Salhan, Raj Sanjay Shah, Alex Warstadt, Ethan Gotlieb Wilcox
Venues:
BabyLM | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
15–23
Language:
URL:
https://aclanthology.org/2026.babylm-main.2/
DOI:
Bibkey:
Cite (ACL):
Ahmet Rıfat Öztürk, Yağız Ekrem Dalar, Nedim Mutlu Sezer, Feyzi Arda Salihoğlu, and Ömer Faruk Aksoy. 2026. Sentence-Level Foresight in Small Language Models: A Diagnostic Study of Learning Signals and Calibration. In Proceedings of the Second BabyLM Workshop, pages 15–23, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Sentence-Level Foresight in Small Language Models: A Diagnostic Study of Learning Signals and Calibration (Öztürk et al., BabyLM 2026)
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PDF:
https://aclanthology.org/2026.babylm-main.2.pdf