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Arnold Overwijk

7 accepted papers

2025

Group-Level Data Selection for Efficient Pretraining

NeurIPS 2025poster

The efficiency and quality of language model pretraining are largely determined by the way pretraining data are selected. In this paper, we introduce *Group-MATES*, an efficient group-level data selection approach to optimize the speed-quality frontier of language model pretraining. Specifically, Gr…

Cited by 0SourcecodeScholar
2025

ORBIT - Open Recommendation Benchmark for Reproducible Research with Hidden Tests

NeurIPS 2025poster

Recommender systems are among the most impactful AI applications, interacting with billions of users every day, guiding them to relevant products, services, or information tailored to their preferences. However, the research and development of recommender systems are hindered by existing datasets th…

Cited by 0SourceScholar
2023

Augmenting Zero-Shot Dense Retrievers with Plug-in Mixture-of-Memories

EMNLP 2023long main

In this paper we improve the zero-shot generalization ability of language models via Mixture-Of-Memory Augmentation (MoMA), a mechanism that retrieves augmentation documents from multiple information corpora (external memories), with the option to ''plug in'' unseen memory at inference time. We deve…

Cited by 0SourcecodeScholar
2022

COCO-DR: Combating the Distribution Shift in Zero-Shot Dense Retrieval with Contrastive and Distributionally Robust Learning

EMNLP 2022main

We present a new zero-shot dense retrieval (ZeroDR) method, COCO-DR, to improve the generalization ability of dense retrieval by combating the distribution shifts between source training tasks and target scenarios. To mitigate the impact of document differences, COCO-DR continues pretraining the lan…

2022

Reduce Catastrophic Forgetting of Dense Retrieval Training with Teleportation Negatives

EMNLP 2022main

In this paper, we investigate the instability in the standard dense retrieval training, which iterates between model training and hard negative selection using the being-trained model. We show the catastrophic forgetting phenomena behind the training instability, where models learn and forget differ…

2021

Approximate Nearest Neighbor Negative Contrastive Learning for Dense Text Retrieval

ICLR 2021poster

Conducting text retrieval in a learned dense representation space has many intriguing advantages. Yet dense retrieval (DR) often underperforms word-based sparse retrieval. In this paper, we first theoretically show the bottleneck of dense retrieval is the domination of uninformative negatives sample…

2021

Less is More: Pretrain a Strong Siamese Encoder for Dense Text Retrieval Using a Weak Decoder

EMNLP 2021main

Dense retrieval requires high-quality text sequence embeddings to support effective search in the representation space. Autoencoder-based language models are appealing in dense retrieval as they train the encoder to output high-quality embedding that can reconstruct the input texts. However, in this…