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Tim Genewein

16 accepted papers

2025

Compression via Pre-trained Transformers: A Study on Byte-Level Multimodal Data

ICML 2025poster

Foundation models are strong data compressors, but when accounting for their parameter size, their compression ratios are inferior to standard compression algorithms. Naively reducing the parameter count does not necessarily help as it deteriorates predictions and, accordingly, compression. We condu…

Cited by 2SourcePDFScholar
2025

LMAct: A Benchmark for In-Context Imitation Learning with Long Multimodal Demonstrations

ICML 2025poster

In this paper, we present a benchmark to pressure-test today’s frontier models’ multimodal decision-making capabilities in the very long-context regime (up to one million tokens) and investigate whether these models can learn from large numbers of expert demonstrations in their context. We evaluate…

Cited by 5SourcePDFScholar
2025

Understanding Prompt Tuning and In-Context Learning via Meta-Learning

NeurIPS 2025spotlight

Prompting is one of the main ways to adapt a pretrained model to target tasks. Besides manually constructing prompts, many prompt optimization methods have been proposed in the literature. Method development is mainly empirically driven, with less emphasis on a conceptual understanding of prompting.…

Cited by 0SourcecodeScholar
2024

Amortized Planning with Large-Scale Transformers: A Case Study on Chess

NeurIPS 2024poster

This paper uses chess, a landmark planning problem in AI, to assess transformers’ performance on a planning task where memorization is futile — even at a large scale. To this end, we release ChessBench, a large-scale benchmark dataset of 10 million chess games with legal move and value annotations (…

2024

Language Modeling Is Compression

ICLR 2024poster

It has long been established that predictive models can be transformed into lossless compressors and vice versa. Incidentally, in recent years, the machine learning community has focused on training increasingly large and powerful self-supervised (language) models. Since these large language models…

2024

Learning Universal Predictors

ICML 2024poster

Meta-learning has emerged as a powerful approach to train neural networks to learn new tasks quickly from limited data by pre-training them on a broad set of tasks. But, what are the limits of meta-learning? In this work, we explore the potential of amortizing the most powerful universal predictor,…

2023

Memory-Based Meta-Learning on Non-Stationary Distributions

ICML 2023poster

Memory-based meta-learning is a technique for approximating Bayes-optimal predictors. Under fairly general conditions, minimizing sequential prediction error, measured by the log loss, leads to implicit meta-learning. The goal of this work is to investigate how far this interpretation can be realize…

2023

Neural Networks and the Chomsky Hierarchy

ICLR 2023top-25%

Reliable generalization lies at the heart of safe ML and AI. However, understanding when and how neural networks generalize remains one of the most important unsolved problems in the field. In this work, we conduct an extensive empirical study (20'910 models, 15 tasks) to investigate whether insight…

2023

Randomized Positional Encodings Boost Length Generalization of Transformers

ACL 2023short

Transformers have impressive generalization capabilities on tasks with a fixed context length. However, they fail to generalize to sequences of arbitrary length, even for seemingly simple tasks such as duplicating a string. Moreover, simply training on longer sequences is inefficient due to the quad…

2023

Self-Predictive Universal AI

NeurIPS 2023poster

Reinforcement Learning (RL) algorithms typically utilize learning and/or planning techniques to derive effective policies. The integration of both approaches has proven to be highly successful in addressing complex sequential decision-making challenges, as evidenced by algorithms such as AlphaZero a…

Cited by 5SourcePDFScholar
2020

Meta-trained agents implement Bayes-optimal agents

NeurIPS 2020spotlight

Memory-based meta-learning is a powerful technique to build agents that adapt fast to any task within a target distribution. A previous theoretical study has argued that this remarkable performance is because the meta-training protocol incentivises agents to behave Bayes-optimally. We empirically in…

Cited by 49SourcePDFScholar
2019

Sinkhorn AutoEncoders

UAI 2019poster

Optimal transport offers an alternative to maximum likelihood for learning generative autoencoding models. We show that minimizing the $p$-Wasserstein distance between the generator and the true data distribution is equivalent to the unconstrained min-min optimization of the $p$-Wasserstein distance…

Cited by 127SourcePDFScholar
2018

The Power of Ensembles for Active Learning in Image Classification

CVPR 2018poster

Deep learning methods have become the de-facto standard for challenging image processing tasks such as image classification. One major hurdle of deep learning approaches is that large sets of labeled data are necessary, which can be prohibitively costly to obtain, particularly in medical image diagn…

2017

An information-theoretic on-line update principle for perception-action coupling

IROS 2017poster

Inspired by findings of sensorimotor coupling in humans and animals, there has recently been a growing interest in the interaction between action and perception in robotic systems [1]. Here we consider perception and action as two serial information channels with limited information-processing capac…

Cited by 18SourceScholar