A Shared Geometry of Difficulty in Multilingual Language Models
Stefano Civelli, Pietro Bernardelle, Nicolò Brunello, Gianluca Demartini
ACL 2026

I am a PhD researcher in Computer Science at The University of Queensland (opens in a new tab). My work examines how large language models represent difficulty and how their behaviour is shaped by context, language, and political bias.
Before starting my PhD, I worked as a Research Assistant at UQ and as an ML engineer at ML cube (opens in a new tab) in Milan. I hold an M.Sc. in Computer Science and Engineering from Politecnico di Milano (opens in a new tab).
I also teach computer science at UQ.
Selected publications
Stefano Civelli, Pietro Bernardelle, Nicolò Brunello, Gianluca Demartini
ACL 2026
Stefano Civelli, Pietro Bernardelle, Nardiena A Pratama, Gianluca Demartini
TIST - Special Issue on Risks and Unintended Harms of Generative AI Systems · 2026
Stefano Civelli, Pietro Bernardelle, Frank Mols, Gianluca Demartini
ICWSM 2026
Experience and education
Researching core aspects of Large Language Models (LLMs) like prompt complexity and bias. Developing novel methods to measure and predict query complexity for LLMs.
Conducted research on LLMs for classification of harmful content. Implemented multimodal ML models in PyTorch. Analyzed Facebook ads for political campaigns. Deployed AWS-based dashboard for campaign analysis.
Developed RL solution for AGV mission time estimation. Implemented classic and distributional RL algorithms for time estimation.
Graduated with 110L/110. Main courses: Machine Learning, Neural Networks, Distributed Systems, Data Streaming, Recommender Systems.
DistinctionMerit-based scholarship · Two consecutive years
Graduated with 109/110. Main courses: software engineering, databases, algorithms & data structures, statistics, linear algebra.
DistinctionBest Freshman Award · 2018–19