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Alexander Wettig

16 accepted papers

2025

How to Train Long-Context Language Models (Effectively)

ACL 2025long

We study continued training and supervised fine-tuning (SFT) of a language model (LM) to make effective use of long-context information. We first establish a reliable evaluation protocol to guide model development—instead of perplexity or simple needle-in-a-haystack (NIAH) tests, we use a broad set…

2025

Metadata Conditioning Accelerates Language Model Pre-training

ICML 2025poster

The vast diversity of styles, domains, and quality levels present in language model pre-training corpora is essential in developing general model capabilities, but efficiently learning and deploying the correct behaviors exemplified in each of these heterogeneous data sources is challenging. To addr…

2025

OLMoE: Open Mixture-of-Experts Language Models

ICLR 2025oral

We introduce OLMoE, a fully open, state-of-the-art language model leveraging sparse Mixture-of-Experts (MoE). OLMoE-1B-7B has 7 billion (B) parameters but uses only 1B per input token. We pretrain it on 5 trillion tokens and further adapt it to create OLMoE-1B-7B-Instruct. Our models outperform all…

2025

Organize the Web: Constructing Domains Enhances Pre-Training Data Curation

ICML 2025poster

Modern language models are trained on large, unstructured datasets consisting of trillions of tokens and obtained by crawling the web. The unstructured nature makes it difficult to reason about their contents and develop systematic approaches to data curation. In this paper, we unpack monolithic web…

Cited by 0SourcePDFScholar
2025

SWE-smith: Scaling Data for Software Engineering Agents

NeurIPS 2025spotlight

Despite recent progress in Language Models (LMs) for software engineering, collecting training data remains a significant pain point. Existing datasets are small, with at most 1,000s of training instances from 11 or fewer GitHub repositories. The procedures to curate such datasets are often complex,…

Cited by 0SourceScholar
2024

Finding Transformer Circuits With Edge Pruning

NeurIPS 2024spotlight

The path to interpreting a language model often proceeds via analysis of circuits---sparse computational subgraphs of the model that capture specific aspects of its behavior. Recent work has automated the task of discovering circuits. Yet, these methods have practical limitations, as they either rel…

2024

Language Models as Science Tutors

ICML 2024poster

NLP has recently made exciting progress toward training language models (LMs) with strong scientific problem-solving skills. However, model development has not focused on real-life use-cases of LMs for science, including applications in education that require processing long scientific documents. To…

2024

QuRating: Selecting High-Quality Data for Training Language Models

ICML 2024spotlight

Selecting high-quality pre-training data is important for creating capable language models, but existing methods rely on simple heuristics. We introduce QuRating, a method for selecting pre-training data that can capture human intuitions about data quality. In this paper, we investigate four qualiti…

2024

SWE-agent: Agent-Computer Interfaces Enable Automated Software Engineering

NeurIPS 2024poster

Language model agents are increasingly being used to automate complicated tasks in digital environments. Just as humans benefit from powerful software applications, such as integrated development environments, for complex tasks like software engineering, we posit that language model agents represent…

Cited by 217SourcePDFScholar
2024

SWE-bench: Can Language Models Resolve Real-world Github Issues?

ICLR 2024oral

Language models have outpaced our ability to evaluate them effectively, but for their future development it is essential to study the frontier of their capabilities. We find real-world software engineering to be a rich, sustainable, and challenging testbed for evaluating the next generation of langu…

Cited by 500SourcePDFScholar
2023

A Kernel-Based View of Language Model Fine-Tuning

ICML 2023poster

It has become standard to solve NLP tasks by fine-tuning pre-trained language models (LMs), especially in low-data settings. There is minimal theoretical understanding of empirical success, e.g., why fine-tuning a model with $10^8$ or more parameters on a couple dozen training points does not result…

2023

Poisoning Retrieval Corpora by Injecting Adversarial Passages

EMNLP 2023short main

Dense retrievers have achieved state-of-the-art performance in various information retrieval tasks, but to what extent can they be safely deployed in real-world applications? In this work, we propose a novel attack for dense retrieval systems in which a malicious user generates a small number of adv…

Cited by 0SourcecodeScholar