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Jörg Bornschein

Alumni

Publications

Fine-Tuned In-Context Learners for Efficient Adaptation
Jörg Bornschein
Clare Lyle
Yazhe Li
Amal Rannen-Triki
Xu Owen He
Razvan Pascanu
When adapting large language models (LLMs) to a specific downstream task, two primary approaches are commonly employed: (1) prompt engineeri… (voir plus)ng, often with in-context few-shot learning, leveraging the model's inherent generalization abilities, and (2) fine-tuning on task-specific data, directly optimizing the model's parameters. While prompt-based methods excel in few-shot scenarios, their effectiveness often plateaus as more data becomes available. Conversely, fine-tuning scales well with data but may underperform when training examples are scarce. We investigate a unified approach that bridges these two paradigms by incorporating in-context learning directly into the fine-tuning process. Specifically, we fine-tune the model on task-specific data augmented with in-context examples, mimicking the structure of k-shot prompts. This approach, while requiring per-task fine-tuning, combines the sample efficiency of in-context learning with the performance gains of fine-tuning, leading to a method that consistently matches and often significantly exceeds both these baselines. To perform hyperparameter selection in the low-data regime, we propose to use prequential evaluation, which eliminates the need for expensive cross-validation and leverages all available data for training while simultaneously providing a robust validation signal. We conduct an extensive empirical study to determine which adaptation paradigm - fine-tuning, in-context learning, or our proposed unified approach offers the best predictive performance on a concrete data downstream-tasks.
2025-12-21
ArXiv (prépublication)
doi.org
arxiv.org
On the generalization of language models from in-context learning and finetuning: a controlled study
Andrew Lampinen
Arslan Chaudhry
Stephanie C.Y. Chan
Cody Wild
Diane Wan
Alexander Y. Ku
Alex Ku
Jörg Bornschein
Razvan Pascanu
Murray P. Shanahan
James L McClelland
2025-04-30
arXiv (publié)
doi.org
arxiv.org
LLMs are Greedy Agents: Effects of RL Fine-tuning on Decision-Making Abilities
Thomas Schmied
Jörg Bornschein
Jordi Grau-Moya
Markus Wulfmeier
Razvan Pascanu
2025-03-31
arXiv (publié)
doi.org
arxiv.org
How do language models learn facts? Dynamics, curricula and hallucinations
Nicolas Zucchet
Jörg Bornschein
Stephanie Chan
Andrew Lampinen
Razvan Pascanu
Soham De
2025-03-26
ArXiv (prépublication)
doi.org
arxiv.org
Revisiting Dynamic Evaluation: Online Adaptation for Large Language Models
Amal Rannen-Triki
Jörg Bornschein
Razvan Pascanu
Marcus Hutter
Andr'as Gyorgy
Alexandre Galashov
Yee Whye Teh
Michalis K. Titsias
We consider the problem of online fine tuning the parameters of a language model at test time, also known as dynamic evaluation. While it is… (voir plus) generally known that this approach improves the overall predictive performance, especially when considering distributional shift between training and evaluation data, we here emphasize the perspective that online adaptation turns parameters into temporally changing states and provides a form of context-length extension with memory in weights, more in line with the concept of memory in neuroscience. We pay particular attention to the speed of adaptation (in terms of sample efficiency),sensitivity to the overall distributional drift, and the computational overhead for performing gradient computations and parameter updates. Our empirical study provides insights on when online adaptation is particularly interesting. We highlight that with online adaptation the conceptual distinction between in-context learning and fine tuning blurs: both are methods to condition the model on previously observed tokens.
2024-02-29
arXiv (publié)
doi.org
arxiv.org
Bridging the Gap Between Offline and Online Reinforcement Learning Evaluation Methodologies
Shiva Kanth Sujit
Pedro Braga
Jörg Bornschein
S Ebrahimi Kahou
Reinforcement learning (RL) has shown great promise with algorithms learning in environments with large state and action spaces purely from … (voir plus)scalar reward signals. A crucial challenge for current deep RL algorithms is that they require a tremendous amount of environment interactions for learning. This can be infeasible in situations where such interactions are expensive, such as in robotics. Offline RL algorithms try to address this issue by bootstrapping the learning process from existing logged data without needing to interact with the environment from the very beginning. While online RL algorithms are typically evaluated as a function of the number of environment interactions, there isn't a single established protocol for evaluating offline RL methods. In this paper, we propose a sequential approach to evaluate offline RL algorithms as a function of the training set size and thus by their data efficiency. Sequential evaluation provides valuable insights into the data efficiency of the learning process and the robustness of algorithms to distribution changes in the dataset while also harmonizing the visualization of the offline and online learning phases. Our approach is generally applicable and easy to implement. We compare several existing offline RL algorithms using this approach and present insights from a variety of tasks and offline datasets.
2023-11-09
TMLR (accepté)
doi.org
openreview.net