Fine-tuning and adaptation

LoRA, PEFT, instruction tuning and domain adaptation — adapting a pretrained model without paying to train one.

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arXiv Machine Learning
Oct 19

Reading the News Without Hindsight: NoLBERT Topics and the Cross-Section of Stock Returns

The paper introduces NoLBERT, a language model pretrained only on financial news from 1976 to 1995, and adapts it into a sentence encoder via contrastive fine‑tuning. It compares NoLBERT’s topic extraction to LDA, MiniLM, and FinBERT on 1.26 million articles from 2012 to 2024, converting topics into attention shocks and stock exposures to forecast returns of the 1,000 largest US stocks across multiple models and rebalancing frequencies. While NoLBERT produces the most stable topics and performs comparably to LDA, the best‑validated model still loses money, and an equal‑weight blend of all readers yields a monthly net Sharpe ratio of 1.12, significant against zero but not against a price‑only benchmark.

By Kevin Foley, Jonathan Hartadi, Shivesh Prakash, Charishma Takkallapalli, Swapnil Vatsal
arXiv Computer Vision
Oct 19

DICL-Qwen3VL: Decoupled Confidence Calibration for Interpretable Workwear Detection

DICL-Qwen3VL is a decoupled, interpretable vision‑language model that localizes upper‑body clothing and identifies workwear in indoor construction sites. It uses low‑rank adaptation of Qwen3‑VL, separates visual and reasoning confidence estimates, and employs token entropy and image perturbation sensitivity to supervise visual confidence. Experiments on the Indoor Construction Site Workwear Dataset and the web‑collected Indoor Construction Workwear Dataset achieve mAP@50 scores of 0.730 and 0.753, outperforming baseline VLMs and providing explicit evidence and confidence scores for industrial safety monitoring.

By Meng Wang, Wu Zeng, Mei Li, Chao He
arXiv Computation and Language
Oct 19

The Chameleon's Limit: Investigating Persona Collapse and Homogenization in Large Language Models

The paper introduces the concept of Persona Collapse, where large language models (LLMs) produce clustered, non-diverse responses in multi-agent simulations. It defines three diagnostic metrics—Coverage, Uniformity, and Complexity—to quantify this phenomenon across eight LLMs on tasks such as personality, moral reasoning, and self-introduction. Findings show that persona collapse is universal but varies by task, cannot be alleviated by sampling more personas, and that higher per-persona fidelity leads to more polarized populations, while persona-targeted fine-tuning further reduces diversity.

By Yunze Xiao, Vivienne J. Zhang, Chenghao Yang, Weihao Xuan, Jen-tse Huang
arXiv Computation and Language
Oct 19

AgentOdyssey: Open-Ended Long-Horizon Text Game Generation for Test-Time Continual Learning Agents

AgentOdyssey is a new evaluation framework that procedurally generates open-ended text games with rich entities, dynamic worlds, and long-horizon tasks to test test-time continual learning agents. The framework measures game progress and provides diagnostic tests on world knowledge acquisition, episodic memory, exploration, action diversity, and model cost. Experiments across six games show that even the best agents fall far short of human performance, and supervised fine-tuning leads to catastrophic forgetting, highlighting the need for better parametric continual learning methods.

By Zheyuan Zhang, Zehao Wen, Alvin Zhang, Andrew Wang, Jianwen Xie, Daniel Khashabi, Tianmin Shu
arXiv AI
Oct 19

Compression Precedes, Content Decides: Emergent Misalignment in Reward Models

The paper investigates emergent misalignment in reward models, showing that fine‑tuning reward models to prefer harmful content in a single domain (medical or financial) causes the preference to generalize to seven other domains. The authors fine‑tune two state‑of‑the‑art reward models—Skywork‑Reward‑V2‑Llama‑3.1‑8B and Skywork‑Reward‑V2‑Qwen3‑8B—and find that the models still perform well on the standard RewardBench 2 evaluation while exhibiting a preference for harm. Mechanistically, the study identifies two key changes in the reward models’ representations: a geometric compression that reduces the angle between sound and harmful responses, and a content‑specific rotation that aligns harmful representations more closely with the scalar head, thereby increasing their reward score.

By Dhruv Puri, Nikhil Prakash