← Search

Oscar Balcells Obeso

2 accepted papers

2025

Do I Know This Entity? Knowledge Awareness and Hallucinations in Language Models

ICLR 2025oral

Hallucinations in large language models are a widespread problem, yet the mechanisms behind whether models will hallucinate are poorly understood, limiting our ability to solve this problem. Using sparse autoencoders as an interpretability tool, we discover that a key part of these mechanisms is ent…

Cited by 10SourcePDFScholar
2024

Refusal in Language Models Is Mediated by a Single Direction

NeurIPS 2024poster

Conversational large language models are fine-tuned for both instruction-following and safety, resulting in models that obey benign requests but refuse harmful ones. While this refusal behavior is widespread across chat models, its underlying mechanisms remain poorly understood. In this work, we sho…