Enhancing LLM Performance via LoRA SFT and DPO for the LM Playschool Challenge

Vasamsetti Nihal Tej, Velineni Harshavaishnav, Shreya Ghosh


Abstract
Large Language Models (LLMs) have achieved SOTA results in many natural language pro- cessing tasks. However, they are primarily trained for static text generation and often strug- gle in interactive, goal-oriented environments that require multi-turn reasoning, state track- ing, and need to give structured output formats. This paper presents our team’s submission to the LM Playschool Workshop Shared Task at EMNLP 2026. The LM Playschool Workshop Shared Task at EMNLP 2026 addresses this challenge by evaluating language models as in- teractive agents in structured dialogue games. We hereby explored different fine-tuning strate- gies for Qwen 4B and Qwen 7B models to improve their interactive capabilities and eval- uated them. We perform a comparison of Su- pervised Fine-Tuning (SFT) and Direct Pref- erence Optimization (DPO) using multi-turn training data. Our study analyzes the effective- ness of each optimization strategy for learning robust dialogue behaviors while maintaining models stability towards interactive games and also not to forget its language linguistics by different evaluating metrics. Experimental re- sults show that although supervised fine-tuning provides consistent interactive performance, di- rectly optimizing the foundation model using DPO reduces optimization errors and leads to improved agent behavior. Our best-performing model achieved a clemscore of 38.23 on the official LM Playschool leaderboard, evaluated using the Playpen workbench.
Anthology ID:
2026.lmplayschool-1.10
Volume:
The Proceedings of Improving Language Models through Learning from Dialogue Game Interaction
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Alessandro Suglia, Mario Giulianelli, David Schlangen, Raffaella Bernardi, Raquel Fernández, Sherzod Hakimov, Sabrina McCallum, Davide Mazzaccara, Dieu-Thu Le, Oliver Lemon, Alexander Koller
Venues:
LM Playschool | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
127–131
Language:
URL:
https://aclanthology.org/2026.lmplayschool-1.10/
DOI:
Bibkey:
Cite (ACL):
Vasamsetti Nihal Tej, Velineni Harshavaishnav, and Shreya Ghosh. 2026. Enhancing LLM Performance via LoRA SFT and DPO for the LM Playschool Challenge. In The Proceedings of Improving Language Models through Learning from Dialogue Game Interaction, pages 127–131, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Enhancing LLM Performance via LoRA SFT and DPO for the LM Playschool Challenge (Tej et al., LM Playschool 2026)
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PDF:
https://aclanthology.org/2026.lmplayschool-1.10.pdf