collaborators

9 papers

cs.LG2026

On Language Drift during RLVR Post-Training

Michael Sullivan, Alexander Koller

Recent advances in LLM reasoning models---driven primarily by the paradigm of post-training via reinforcement learning with verifiable reward (RLVR)---have enabled them to accompli…

cs.CL2026

On the (In)effectiveness of AMR Augmentation for Large Language Models

Hoa Quynh Nhung Nguyen, Jacopo Staiano, Michael Sullivan

While Abstract Meaning Representation (AMR) has historically improved performance on a range of NLP tasks, the benefit---or lack thereof---of AMR augmentation for modern LLMs is th…

cs.AI2026

Accelerating Constrained Decoding with Token Space Compression

Michael Sullivan, Alexander Koller

To guarantee that an LLM's outputs conform to a specified structure, context-free grammar (CFG) decoding engines force the selection of next tokens to produce strings that conform…

cs.CL2026

AuthorMix: Modular Authorship Style Transfer via Layer-wise Adapter Mixing

Sarubi Thillainathan, Ji-Ung Lee, Michael Sullivan +1

The task of authorship style transfer involves rewriting text in the style of a target author while preserving the meaning of the original text. Existing style transfer methods tra…

cs.CL2025

Evaluating Spatiotemporal Consistency in Automatically Generated Sewing Instructions

Luisa Geiger, Mareike Hartmann, Michael Sullivan +1

In this paper, we propose a novel, automatic tree-based evaluation metric for LLM-generated step-by-step assembly instructions, that more accurately reflects spatiotemporal aspects…

cs.LG2025

GRPO is Secretly a Process Reward Model

Michael Sullivan, Alexander Koller

Process reward models (PRMs) allow for fine-grained credit assignment in reinforcement learning (RL), and seemingly contrast with outcome reward models (ORMs), which assign a singl…

cs.LG2025

Procedural Environment Generation for Tool-Use Agents

Michael Sullivan, Mareike Hartmann, Alexander Koller

Although the power of LLM tool-use agents has ignited a flurry of recent research in this area, the curation of tool-use training data remains an open problemespecially for onli…

cs.CL2025

Exploring Graph Representations of Logical Forms for Language Modeling

Michael Sullivan

We make the case for language models over logical forms (LFLMs), arguing that such models are more data-efficient than their textual counterparts. To that end, we introduce the Gra…

cs.CL2025

Playpen: An Environment for Exploring Learning Through Conversational Interaction

Nicola Horst, Davide Mazzaccara, Antonia Schmidt +13

Interaction between learner and feedback-giver has come into focus recently for post-training of Large Language Models (LLMs), through the use of reward models that judge the appro…