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Tomas Pfister

75 accepted papers

2026

ATLAS: Constraints-Aware Multi-Agent Collaboration for Real-World Travel Planning

ICLR 2026poster

While Large Language Models (LLMs) have shown remarkable advancements in reasoning and tool use, they often fail to generate optimal, grounded solutions under complex constraints. Real-world travel planning exemplifies these challenges, evaluating agents’ abilities to handle constraints that are exp…

Cited by 12SourceScholar
2026

CausalArmor: Efficient Indirect Prompt Injection Guardrails via Causal Attribution

ICML 2026poster

AI agents equipped with tool-calling capabilities are susceptible to *Indirect Prompt Injection* (IPI) attacks. In this attack scenario, malicious commands hidden within *untrusted* content trick the agent into performing unauthorized actions. Existing defenses can reduce attack success but often su…

Cited by 0SourceScholar
2026

Co-RedTeam: Orchestrated Security Discovery and Exploitation with LLM Agents

ICML 2026poster

Large language models (LLMs) have shown promise in assisting cybersecurity tasks, yet existing approaches struggle with automatic vulnerability discovery and exploitation due to limited interaction, weak execution grounding, and a lack of experience reuse. We propose Co-RedTeam, a security-aware mul…

Cited by 0SourceScholar
2026

CoDA: Agentic Systems for Collaborative Data Visualization

ICLR 2026poster

Automating data visualization from natural language is crucial for data science, yet current systems struggle with complex datasets containing multiple files and iterative refinement. Existing approaches, including simple single- or multi-agent systems, often oversimplify the task, focusing on initi…

Cited by 0SourcecodeScholar
2026

MARS: Modular Agent with Reflective Search for Automated AI Research

ICML 2026poster

Automating AI research differs from general software engineering due to computationally expensive evaluation (e.g., model training) and opaque performance attribution. Current LLM-based agents struggle here, often generating monolithic scripts that ignore execution costs and causal factors. We intro…

Cited by 0SourceScholar
2026

PaperBanana: Automating Academic Illustration for AI Scientists

ICML 2026spotlight

Despite rapid advances in autonomous AI scientists powered by language models, generating publication-ready illustrations remains a labor-intensive bottleneck in the research workflow. To lift this burden, we introduce PaperBanana, an agentic framework for automated generation of publication-ready a…

Cited by 0SourceScholar
2026

ReasoningBank: Scaling Agent Self-Evolving with Reasoning Memory

ICLR 2026poster

With the growing adoption of large language model (LLM) agents in persistent, real-world roles, they naturally encounter continuous streams of tasks and interactions. A key limitation, however, is their failure to learn from this accumulated experience, forcing them to discard valuable insights and…

Cited by 0SourcecodeScholar
2026

Supervised Reinforcement Learning: From Expert Trajectories to Step-wise Reasoning

ICLR 2026poster

Large Language Models (LLMs) often struggle with challenging, multi-step reasoning problems due to a fundamental learning gap -- Reinforcement Learning with Verifiable Rewards (RLVR) suffers from sparse rewards when correct solutions are rarely sampled, while Supervised Fine-Tuning (SFT) tends to ov…

Cited by 0SourceScholar
2026

TFRBench: A Reasoning Benchmark for Evaluating Forecasting Systems

ICML 2026poster

We introduce TFRBench, the first benchmark designed to evaluate the reasoning capabilities of forecasting systems. Traditionally, time-series forecasting has been evaluated solely on numerical accuracy, treating foundation models as "black boxes." Unlike existing benchmarks, TFRBench provides a prot…

Cited by 0SourceScholar
2026

TUMIX: Multi-Agent Test-Time Scaling with Tool-Use Mixture

ICLR 2026poster

While integrating tools like Code Interpreter and Search has significantly enhanced Large Language Model (LLM) reasoning in models like ChatGPT Agent and Gemini-Pro, practical guidance on optimal tool use is lacking. The core challenge is effectively combining textual reasoning, coding, and search f…

Cited by 0SourceScholar
2026

The ACE Protocol: Operationalizing Language Model Activations for Better Calibration and Utility

ICML 2026poster

As language models improve and become increasingly deployed to solve a variety of tasks, trustworthiness becomes essential. Calibration is a good proxy for trust: well-calibrated confidence estimates help inform the risk versus reward trade-off when trusting a specific model output. Unfortunately, e…

Cited by 0SourceScholar
2026

VISTA: A Test-Time Self-Improving Video Generation Agent

CVPR 2026

Despite rapid advances in text-to-video synthesis, generated video quality remains critically dependent on precise user prompts. Existing test-time optimization methods, successful in other domains, struggle with the multi-faceted nature of video. In this work, we introduce VISTA (Video Iterative Se

Cited by 0SourcecodeScholar
2026

Watch and Learn: Learning to Use Computers from Online Videos

CVPR 2026

Computer-using agents (CUAs) must plan task workflows across diverse and evolving applications, yet progress is limited by the lack of large-scale, high-quality training data. Existing datasets are narrow, static, and costly to annotate, while synthetic data often yields oversimplified or misaligned

Cited by 0SourceScholar
2025

Heterogeneous Swarms: Jointly Optimizing Model Roles and Weights for Multi-LLM Systems

NeurIPS 2025poster

We propose Heterogeneous Swarms, an algorithm to design multi-LLM systems by jointly optimizing model roles and weights. We represent multi-LLM systems as directed acyclic graphs (DAGs) of LLMs with topological message passing for collaborative generation. Given a pool of LLM experts and a utility f…

Cited by 0SourceScholar
2025

In Prospect and Retrospect: Reflective Memory Management for Long-term Personalized Dialogue Agents

ACL 2025long

Large Language Models (LLMs) have made significant progress in open-ended dialogue, yet their inability to retain and retrieve relevant information from long-term interactions limits their effectiveness in applications requiring sustained personalization. External memory mechanisms have been propose…

2025

Learning to Clarify: Multi-turn Conversations with Action-Based Contrastive Self-Training

ICLR 2025poster

Large language models (LLMs), optimized through human feedback, have rapidly emerged as a leading paradigm for developing intelligent conversational assistants. However, despite their strong performance across many benchmarks, LLM-based agents might still lack conversational skills such as disambigu…

Cited by 8SourcePDFScholar
2025

MLE-STAR: Machine Learning Engineering Agent via Search and Targeted Refinement

NeurIPS 2025poster

Agents based on large language models (LLMs) for machine learning engineering (MLE) can automatically implement ML models via code generation. However, existing approaches to build such agents often rely heavily on inherent LLM knowledge and employ coarse exploration strategies that modify the entir…

Cited by 0SourceScholar
2025

Magnet: Multi-turn Tool-use Data Synthesis and Distillation via Graph Translation

ACL 2025long

Large language models (LLMs) have exhibited the ability to effectively utilize external tools to address user queries. However, their performance may be limited in complex, multi-turn interactions involving users and multiple tools. To address this, we propose Magnet, a principled framework for synt…

Cited by 0SourcePDFScholar
2025

Mitigating Object Hallucination in MLLMs via Data-augmented Phrase-level Alignment

ICLR 2025poster

Despite their significant advancements, Multimodal Large Language Models (MLLMs) often generate factually inaccurate information, referred to as hallucination. In this work, we address object hallucinations in MLLMs, where information is generated about an object not present in the input image. We i…

Cited by 0SourcePDFScholar
2025

Model Swarms: Collaborative Search to Adapt LLM Experts via Swarm Intelligence

ICML 2025poster

We propose Model Swarms, a collaborative search algorithm to adapt LLMs via swarm intelligence, the collective behavior guiding individual systems. Specifically, Model Swarms starts with a pool of LLM experts and a utility function. Guided by the best-found checkpoints across models, diverse LLM exp…

Cited by 6SourcePDFScholar
2025

PLAN-TUNING: Post-Training Language Models to Learn Step-by-Step Planning for Complex Problem Solving

EMNLP 2025

Recently, decomposing complex problems into simple subtasks–a crucial part of human-like natural planning–to solve the given problem has significantly boosted the performance of large language models (LLMs). However, leveraging such planning structures during post-training to boost the performance o

Cited by 0SourcePDFScholar
2025

PlanGEN: A Multi-Agent Framework for Generating Planning and Reasoning Trajectories for Complex Problem Solving

EMNLP 2025

Recent agent frameworks and inference-time algorithms often struggle with natural planning problems due to limitations in verifying generated plans or reasoning and varying complexity of instances within a single task. Many existing methods for these tasks either perform task-level verification with

Cited by 0SourcePDFScholar
2025

Reverse Thinking Makes LLMs Stronger Reasoners

NAACL 2025long

Reverse thinking plays a crucial role in human reasoning. Humans can reason not only from a problem to a solution but also in reverse, i.e., start from the solution and reason towards the problem. This often enhances overall reasoning performance as it enables consistency checks between their forwar…

Cited by 3SourcePDFScholar
2025

Speculative Knowledge Distillation: Bridging the Teacher-Student Gap Through Interleaved Sampling

ICLR 2025poster

Recent advances in knowledge distillation (KD) have enabled smaller student models to approach the performance of larger teacher models. However, popular methods such as supervised KD and on-policy KD, are adversely impacted by the knowledge gaps between teacher-student in practical scenarios. Super…

Cited by 5SourcePDFScholar
2025

Speculative RAG: Enhancing Retrieval Augmented Generation through Drafting

ICLR 2025poster

Retrieval augmented generation (RAG) combines the generative abilities of large language models (LLMs) with external knowledge sources to provide more accurate and up-to-date responses. Recent RAG advancements focus on improving retrieval outcomes through iterative LLM refinement or self-critique ca…

Cited by 13SourcePDFScholar
2024

CaLM: Contrasting Large and Small Language Models to Verify Grounded Generation

ACL 2024findings

Grounded generation aims to equip language models (LMs) with the ability to produce more credible and accountable responses by accurately citing verifiable sources. However, existing methods, by either feeding LMs with raw or preprocessed materials, remain prone to errors. To address this, we introd…

2024

Chain of Agents: Large Language Models Collaborating on Long-Context Tasks

NeurIPS 2024poster

Addressing the challenge of effectively processing long contexts has become a critical issue for Large Language Models (LLMs). Two common strategies have emerged: 1) reducing the input length, such as retrieving relevant chunks by Retrieval-Augmented Generation (RAG), and 2) expanding the context wi…

Cited by 31SourcePDFScholar
2024

Chain-of-Table: Evolving Tables in the Reasoning Chain for Table Understanding

ICLR 2024poster

Table-based reasoning with large language models (LLMs) is a promising direction to tackle many table understanding tasks, such as table-based question answering and fact verification. Compared with generic reasoning, table-based reasoning requires the extraction of underlying semantics from both fr…

Cited by 107SourcePDFScholar
2024

CodecLM: Aligning Language Models with Tailored Synthetic Data

NAACL 2024findings

Instruction tuning has emerged as the key in aligning large language models (LLMs) with specific task instructions, thereby mitigating the discrepancy between the next-token prediction objective and users’ actual goals. To reduce the labor and time cost to collect or annotate data by humans, researc…

2024

Effective Large Language Model Adaptation for Improved Grounding and Citation Generation

NAACL 2024long

Large language models (LLMs) have achieved remarkable advancements in natural language understanding and generation. However, one major issue towards their widespread deployment in the real world is that they can generate “hallucinated” answers that are not factual.Towards this end, this paper focus…

Cited by 32SourcePDFScholar
2024

Found in the middle: Calibrating Positional Attention Bias Improves Long Context Utilization

ACL 2024findings

Large language models (LLMs), even when specifically trained to process long input contexts, struggle to capture relevant information located in the middle of their input. This phenomenon has been known as the lost-in-the-middle problem. In this work, we make three contributions. First, we set out t…

2024

Large Language Models Can Automatically Engineer Features for Few-Shot Tabular Learning

ICML 2024poster

Large Language Models (LLMs), with their remarkable ability to tackle challenging and unseen reasoning problems, hold immense potential for tabular learning, that is vital for many real-world applications. In this paper, we propose a novel in-context learning framework, FeatLLM, which employs LLMs a…

2024

Matryoshka-Adaptor: Unsupervised and Supervised Tuning for Smaller Embedding Dimensions

EMNLP 2024main

Embeddings from Large Language Models (LLMs) have emerged as critical components in various applications, particularly for information retrieval. While high-dimensional embeddings generally demonstrate superior performance as they contain more salient information, their practical application is freq…

Cited by 1SourcePDFScholar
2024

Re-Invoke: Tool Invocation Rewriting for Zero-Shot Tool Retrieval

EMNLP 2024finding

Recent advances in large language models (LLMs) have enabled autonomous agents with complex reasoning and task-fulfillment capabilities using a wide range of tools. However, effectively identifying the most relevant tools for a given task becomes a key bottleneck as the toolset size grows, hindering…

Cited by 5SourcePDFScholar
2024

Search-Adaptor: Embedding Customization for Information Retrieval

ACL 2024long

Embeddings extracted by pre-trained Large Language Models (LLMs) have significant potential to improve information retrieval and search. Beyond the zero-shot setup in which they are being conventionally used, being able to take advantage of the information from the relevant query-corpus paired data…

2024

TEMPO: Prompt-based Generative Pre-trained Transformer for Time Series Forecasting

ICLR 2024poster

The past decade has witnessed significant advances in time series modeling with deep learning. While achieving state-of-the-art results, the best-performing architectures vary highly across applications and domains. Meanwhile, for natural language processing, the Generative Pre-trained Transformer (…

2024

TableRAG: Million-Token Table Understanding with Language Models

NeurIPS 2024poster

Recent advancements in language models (LMs) have notably enhanced their ability to reason with tabular data, primarily through program-aided mechanisms that manipulate and analyze tables. However, these methods often require the entire table as input, leading to scalability challenges due to the po…

2024

TextGenSHAP: Scalable Post-Hoc Explanations in Text Generation with Long Documents

ACL 2024findings

Large language models (LLMs) have attracted great interest in many real-world applications; however, their “black-box” nature necessitates scalable and faithful explanations. Shapley values have matured as an explainability method for deep learning, but extending them to LLMs is difficult due to lon…

Cited by 5SourcePDFScholar
2023

Adaptation with Self-Evaluation to Improve Selective Prediction in LLMs

EMNLP 2023long findings

Large language models (LLMs) have recently shown great advances in a variety of tasks, including natural language understanding and generation. However, their use in high-stakes decision-making scenarios is still limited due to the potential for errors. *Selective prediction* is a technique that can…

Cited by 0SourceScholar
2023

Better Zero-Shot Reasoning with Self-Adaptive Prompting

ACL 2023findings

Modern large language models (LLMs) have demonstrated impressive capabilities at sophisticated tasks, often through step-by-step reasoning similar to humans. This is made possible by their strong few- and zero-shot abilities – they can effectively learn from a handful of handcrafted, completed respo…

2023

Distilling Step-by-Step! Outperforming Larger Language Models with Less Training Data and Smaller Model Sizes

ACL 2023findings

Deploying large language models (LLMs) is challenging because they are memory inefficient and compute-intensive for practical applications. In reaction, researchers train smaller task-specific models by either finetuning with human labels or distilling using LLM-generated labels. However, finetuning…

2023

FormNetV2: Multimodal Graph Contrastive Learning for Form Document Information Extraction

ACL 2023long

The recent advent of self-supervised pre-training techniques has led to a surge in the use of multimodal learning in form document understanding. However, existing approaches that extend the mask language modeling to other modalities require careful multi-task tuning, complex reconstruction target d…

2023

Neural Spline Search for Quantile Probabilistic Modeling

AAAI 2023technical

Accurate estimation of output quantiles is crucial in many use cases, where it is desired to model the range of possibility. Modeling target distribution at arbitrary quantile levels and at arbitrary input attribute levels are important to offer a comprehensive picture of the data, and requires the…

Cited by 5SourcePDFScholar
2023

Pic2Word: Mapping Pictures to Words for Zero-Shot Composed Image Retrieval

CVPR 2023poster

In Composed Image Retrieval (CIR), a user combines a query image with text to describe their intended target. Existing methods rely on supervised learning of CIR models using labeled triplets consisting of the query image, text specification, and the target image. Labeling such triplets is expensive…

2023

Prefix Conditioning Unifies Language and Label Supervision

CVPR 2023poster

Pretraining visual models on web-scale image-caption datasets has recently emerged as a powerful alternative to traditional pretraining on image classification data. Image-caption datasets are more "open-domain", containing broader scene types and vocabulary words, and result in models that have str…

Cited by 15SourcePDFScholar
2023

QueryForm: A Simple Zero-shot Form Entity Query Framework

ACL 2023findings

Zero-shot transfer learning for document understanding is a crucial yet under-investigated scenario to help reduce the high cost involved in annotating document entities. We present a novel query-based framework, QueryForm, that extracts entity values from form-like documents in a zero-shot fashion.…

Cited by 7SourcePDFScholar
2023

Universal Self-Adaptive Prompting

EMNLP 2023long main

A hallmark of modern large language models (LLMs) is their impressive general zero-shot and few-shot abilities, often elicited through in-context learning (ICL) via prompting. However, while highly coveted and being the most general, zero-shot performances in LLMs are still typically weaker due to t…

Cited by 0SourceScholar
2022

Decoupling Local and Global Representations of Time Series

AISTATS 2022poster

Real-world time series data are often generated from several sources of variation. Learning representations that capture the factors contributing to this variability enables better understanding of the data via its underlying generative process and can lead to improvements in performance on downstre…

2022

DualPrompt: Complementary Prompting for Rehearsal-Free Continual Learning

ECCV 2022poster

"Continual learning aims at enabling a single model to learn a sequence of tasks without catastrophic forgetting. Top-performing methods usually require a rehearsal buffer to store past pristine examples for experience replay, which, however, limits their practical values due to privacy and memory c…

2022

FormNet: Structural Encoding beyond Sequential Modeling in Form Document Information Extraction

ACL 2022long

Sequence modeling has demonstrated state-of-the-art performance on natural language and document understanding tasks. However, it is challenging to correctly serialize tokens in form-like documents in practice due to their variety of layout patterns. We propose FormNet, a structure-aware sequence mo…

Cited by 87SourcePDFScholar
2022

Learning Instance-Specific Adaptation for Cross-Domain Segmentation

ECCV 2022poster

"We propose a test-time adaptation method for cross-domain image segmentation. Our method is simple: Given a new unseen instance at the test time, we adapt a pre-trained model by conducting instance-specific BatchNorm (statistics) calibration. Our approach has two core components. First, we replace…

Cited by 16SourcePDFScholar
2022

Learning To Prompt for Continual Learning

CVPR 2022poster

The mainstream paradigm behind continual learning has been to adapt the model parameters to non-stationary data distributions, where catastrophic forgetting is the central challenge. Typical methods rely on a rehearsal buffer or known task identity at test time to retrieve learned knowledge and addr…

Cited by 979PDFcodeScholar
2022

Learning from Weakly-Labeled Web Videos via Exploring Sub-concepts

AAAI 2022technical

Learning visual knowledge from massive weakly-labeled web videos has attracted growing research interests thanks to the large corpus of easily accessible video data on the Internet. However, for video action recognition, the action of interest might only exist in arbitrary clips of untrimmed web vid…

Cited by 7SourcePDFScholar
2022

Nested Hierarchical Transformer: Towards Accurate, Data-Efficient and Interpretable Visual Understanding

AAAI 2022technical

Hierarchical structures are popular in recent vision transformers, however, they require sophisticated designs and massive datasets to work well. In this paper, we explore the idea of nesting basic local transformers on non-overlapping image blocks and aggregating them in a hierarchical way. We find…

2021

Controlling Neural Networks with Rule Representations

NeurIPS 2021poster

We propose a novel training method that integrates rules into deep learning, in a way the strengths of the rules are controllable at inference. Deep Neural Networks with Controllable Rule Representations (DeepCTRL) incorporates a rule encoder into the model coupled with a rule-based objective, enabl…

Cited by 50SourcePDFScholar
2021

CutPaste: Self-Supervised Learning for Anomaly Detection and Localization

CVPR 2021poster

We aim at constructing a high performance model for defect detection that detects unknown anomalous patterns of an image without anomalous data. To this end, we propose a two-stage framework for building anomaly detectors using normal training data only. We first learn self-supervised deep represent…

Cited by 1095PDFScholar
2021

Learning and Evaluating Representations for Deep One-Class Classification

ICLR 2021poster

We present a two-stage framework for deep one-class classification. We first learn self-supervised representations from one-class data, and then build one-class classifiers on learned representations. The framework not only allows to learn better representations, but also permits building one-class…

2021

PseudoSeg: Designing Pseudo Labels for Semantic Segmentation

ICLR 2021poster

Recent advances in semi-supervised learning (SSL) demonstrate that a combination of consistency regularization and pseudo-labeling can effectively improve image classification accuracy in the low-data regime. Compared to classification, semantic segmentation tasks require much more intensive labelin…

2021

ROPE: Reading Order Equivariant Positional Encoding for Graph-based Document Information Extraction

ACL 2021short

Natural reading orders of words are crucial for information extraction from form-like documents. Despite recent advances in Graph Convolutional Networks (GCNs) on modeling spatial layout patterns of documents, they have limited ability to capture reading orders of given word-level node representatio…

Cited by 30SourcePDFScholar
2020

Consistency-based Semi-supervised Active Learning: Towards Minimizing Labeling Cost

ECCV 2020poster

Active learning (AL) combines data labeling and model training to minimize the labeling cost by prioritizing the selection of high value data that can best improve model performance. In pool-based active learning, accessible unlabeled data are not used for model training in most conventional methods…

Cited by 237SourcePDFScholar
2020

Differentiable Top-k with Optimal Transport

NeurIPS 2020poster

Finding the k largest or smallest elements from a collection of scores, i.e., top-k operation, is an important model component widely used in information retrieval, machine learning, and data mining. However, if the top-k operation is implemented in an algorithmic way, e.g., using bubble algorithm,…

2020

Distilling Effective Supervision From Severe Label Noise

CVPR 2020poster

Collecting large-scale data with clean labels for supervised training of neural networks is practically challenging. Although noisy labels are usually cheap to acquire, existing methods suffer a lot from label noise. This paper targets at the challenge of robust training at high label noise regimes.…

Cited by 174PDFcodeScholar
2020

Interpretable Sequence Learning for Covid-19 Forecasting

NeurIPS 2020spotlight

We propose a novel approach that integrates machine learning into compartmental disease modeling (e.g., SEIR) to predict the progression of COVID-19. Our model is explainable by design as it explicitly shows how different compartments evolve and it uses interpretable encoders to incorporate covariat…

Cited by 106SourcePDFScholar
2020

Learning to Transfer Learn: Reinforcement Learning-Based Selection for Adaptive Transfer Learning

ECCV 2020poster

We propose a novel adaptive transfer learning framework, learning to transfer learn (L2TL), to improve performance on a target dataset by careful extraction of the related information from a source dataset. Our framework considers cooperative optimization of shared weights between models for source…

2020

On Completeness-aware Concept-Based Explanations in Deep Neural Networks

NeurIPS 2020poster

Human explanations of high-level decisions are often expressed in terms of key concepts the decisions are based on. In this paper, we study such concept-based explainability for Deep Neural Networks (DNNs). First, we define the notion of \emph{completeness}, which quantifies how sufficient a particu…

2017

Learning From Simulated and Unsupervised Images Through Adversarial Training

CVPR 2017oral

With recent progress in graphics, it has become more tractable to train models on synthetic images, potentially avoiding the need for expensive annotations. However, learning from synthetic images may not achieve the desired performance due to a gap between synthetic and real image distributions. To…

Cited by 2368PDFScholar