Research
Understanding and trusting language models
When language models get things wrong, and how to tell: hallucinations, machine-generated text, uncertainty.
Language models are now used to search, summarise and write, but they can be confidently wrong. We study how they behave and where their limits are: spotting invented facts (hallucinations), telling machine-generated text from human writing, testing whether models understand cause and effect, and checking systems that answer questions from documents.
We also look inside models to understand how they reach their outputs, for example at which point a model decides which writing system to use.
Projects
Language preference and hallucination in multilingual retrieval-augmented generation
Do language models prefer some languages over others when answering from documents? We test this for chatbots that answer questions from a collection of documents in several languages.
Research
2026
Coordination of IDSIA's participation in the Swiss AI Initiative
Coordinated IDSIA's part in the national effort to build and apply large AI models on the Alps supercomputer at CSCS.
Research
2024
UBS–IDSIA AI Lab collaboration
The NLP group participates in the collaboration across different NLP-related projects.
Applied
2024–now
· Industry
Detecting misinformation and machine-generated text
Developed and tested ways to detect misleading content and text written by language models. Produced the BUST benchmark.
Research
2023
Misinformation in social media during COVID-19
Studied how to identify misinformation on social media, and public stance towards health policies, during the pandemic.
Research
2021–2022
People
Publications
Script Choice in LLMs: Evidence for Late-Layer Commitment
Findings of EMNLP 2026, Budapest, Hungary, 2026
Are the LLMs Capable of Maintaining at Least the Language Genus?
Proceedings of the Thirty-Second Language Resources and Evaluation Conference (LREC 2026), 2026
Oscar William Lithgow-Serrano,
David Kletz,
Vani Kanjirangat, David Adametz, Marzio Lunghi, Claudio Bonesana, Matilde Tristany-Farinha, Yuntao Li, Detlef Repplinger, Marco Pierbattista, Stefania Stan, Oleg Szehr
Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025), 2025
Presenting LLMs' Collective Intelligence Approach for Multilingual Hallucination Detection
Proceedings of the 9th edition of the Swiss Text Analytics Conference, 2025
Proceedings of the Workshop on DeTermIt! Evaluating Text Difficulty in a Multilingual Context @ LREC-COLING 2024, 2024
On the Limitations of Zero-Shot Classification of Causal Relations by LLMs (Work in Progress)
CEUR Workshop Proceedings, 2024