Distributional alignment · Uncertainty ETH Zürich × University of Zürich

Alignment beyond the verifiable.

People instruct agents in natural language, which leaves a fuzzy and unverifiable part. I study how to make LLMs and agents trustworthy on that part.

A language model's reasoning runs as a steady signal until it hits a spike of uncertainty, where a human reviewer steps in to check it.

About · Research

Research vision.

I am a PhD candidate under the joint supervision of Prof. Elliott Ash and Prof. Mrinmaya Sachan at ETH Zurich, and Prof. Markus Leippold at University of Zurich. I divide my time equally between both institutions.

People instruct agents and write rubrics in natural language, which leaves a fuzzy and unverifiable part whose ground truth is a distribution of human judgments rather than a point answer. I believe that getting this part right, so that a model matches the distribution of human judgments and knows how well it knows that distribution, is key to teaching AI taste, preventing reward hacking, and aligning AI beyond the verifiable.

My PhD work covers two foundations: judgment with fuzzy criteria, evaluating and improving how LLMs handle human disagreement and building human-AI collaborative annotation tools, and uncertainty quantification that reads a model's beliefs about its own answers from its hidden states.

Selected work

Research highlights.

Fuzzy criteria · Disagreement

Evaluating and improving how LLMs handle fuzzy criteria

LLM judges inherit the fuzzy part of a rubric, so I test models against distributions of human judgments rather than a majority label. Can Reasoning Help LLMs Capture Human Annotator Disagreement? finds that models collapse legitimate disagreement into one overconfident answer, and that RLVR-style reasoning training makes this worse. DIRAS learns calibrated judgments under nuanced natural-language criteria and distills them into small models.

Fuzzy criteria · Tools

Human-AI collaborative annotation tools

Judgment under fuzzy criteria needs people in the loop, and the tool decides where their judgment goes. Co-DETECT lets an expert refine a rough codebook: it uses annotation uncertainty to surface edge cases the codebook does not cover, induces generalizable rules for them, and leaves the expert in charge of what enters the codebook. AFaCTA calibrates LLM annotators on a small human set and routes items between people and models, so validated labels scale into benchmarks.

Uncertainty quantification

Reading a model's beliefs from its hidden states

The spread of human judgments is irreducible. A model's uncertainty about that spread is not, and it is what a clarification question can resolve. ReProbe reads a frozen LLM's internal states to estimate the credibility of each reasoning step, enabling efficient verification and test-time search without a large process reward model. BELT reads a model's beliefs about its current and future answer from the same hidden states and fits a small stopping policy on them, so one probe serves different accuracy-cost trade-offs and transfers from math to coding and agentic tasks.

Projects · Talks · Service

Community collaboration and services.

Collaboration

Apertus: Democratizing Open and Compliant LLMs

Community collaboration on democratizing open and compliant LLMs for global language environments, with contributions to trustworthiness post-training.

Technical report →

Collaboration

When AI Benchmarks Plateau

Community collaboration accepted to ICML 2026 on benchmark saturation and how plateauing scores affect evaluation practice.

ICML 2026 →

Invited Talk

Keynote at the AI4Law Workshop, ICML 2026

Keynote speech at the AI4Law workshop at ICML 2026 on uncertainty-aware LLM reasoning for legal tasks.

Slides →

Publications

Selected research

Distributional alignment to fuzzy human criteria, human-AI collaborative annotation tools, and uncertainty quantification.

Education

Academic path

Mar 2023 – Present

PhD @ ETH D-GESS

ETH Zürich & University of Zürich

Sept 2021 – Sept 2022

MSc in Data Science & Machine Learning

University College London

Sep 2017 – Sep 2021

BEng in Computer Science

University of Hong Kong