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Andre Martins

34 accepted papers

2026

AdaSplash-2: Faster Differentiable Sparse Attention

ICML 2026poster

Sparse attention has been proposed as a way to alleviate the quadratic cost of transformers, a central bottleneck in long-context training. A promising line of work is $\alpha$-entmax attention, a differentiable sparse alternative to softmax that enables input-dependent sparsity yet has lagged behin…

Cited by 0SourceScholar
2026

Long-Context Generalization with Sparse Attention

ICLR 2026poster

Transformer-based architectures traditionally employ softmax to compute attention weights, which produces dense distributions over all tokens in a sequence. While effective in many settings, this density has been shown to be detrimental for tasks that demand precise focus on fixed-size patterns…

Cited by 0SourcecodeScholar
2026

Should We Still Pretrain Encoders with Masked Language Modeling?

ICLR 2026poster

Learning high-quality text representations is fundamental to a wide range of NLP tasks. While encoder pretraining has traditionally relied on Masked Language Modeling (MLM), recent evidence suggests that decoder models pretrained with Causal Language Modeling (CLM) can be effectively repurposed as e…

Cited by 0SourceScholar
2025

$\infty$-Video: A Training-Free Approach to Long Video Understanding via Continuous-Time Memory Consolidation

ICML 2025poster

Current video-language models struggle with long-video understanding due to limited context lengths and reliance on sparse frame subsampling, which often leads to information loss. In this paper, we introduce $\infty$-Video, which is able to process arbitrarily long videos through a continuous-time…

2025

A Recipe of Parallel Corpora Exploitation for Multilingual Large Language Models

NAACL 2025findings

Recent studies have highlighted the potential of exploiting parallel corpora to enhance multilingual large language models, improving performance in both bilingual tasks, e.g., machine translation, and general-purpose tasks, e.g., text classification. Building upon these findings, our comprehensive…

Cited by 2SourcePDFScholar
2025

Different Speech Translation Models Encode and Translate Speaker Gender Differently

ACL 2025short

Recent studies on interpreting the hidden states of speech models have shown their ability to capture speaker-specific features, including gender. Does this finding also hold for speech translation (ST) models? If so, what are the implications for the speaker’s gender assignment in translation? We a…

Cited by 0SourcePDFScholar
2025

From Tower to Spire: Adding the Speech Modality to a Translation-Specialist LLM

EMNLP 2025

We introduce Spire, a speech-augmented language model (LM) capable of both translating and transcribing speech input from English into 10 other languages as well as translating text input in both language directions. Spire integrates the speech modality into an existing multilingual LM via speech di

2025

Global MMLU: Understanding and Addressing Cultural and Linguistic Biases in Multilingual Evaluation

ACL 2025long

Reliable multilingual evaluation is difficult, and culturally appropriate evaluation is even harder to achieve.A common practice to fill this gap is to machine-translate English evaluation sets. However, translation introduces language bias and carries over cultural and regional assumptions from the…

Cited by 0SourcePDFScholar
2025

LLMs instead of Human Judges? A Large Scale Empirical Study across 20 NLP Evaluation Tasks

ACL 2025short

There is an increasing trend towards evaluating NLP models with LLMs instead of human judgments, raising questions about the validity of these evaluations, as well as their reproducibility in the case of proprietary models. We provide JUDGE-BENCH, an extensible collection of 20 NLP datasets with hum…

2025

Sparse Activations as Conformal Predictors

AISTATS 2025poster

Conformal prediction is a distribution-free framework for uncertainty quantification that replaces point predictions with sets, offering marginal coverage guarantees (i.e., ensuring that the sets contain the true label with a specified probability, in expectation). In this paper, we uncover a novel…

Cited by 0SourcecodeScholar
2025

Translate Smart, not Hard: Cascaded Translation Systems with Quality-Aware Deferral

EMNLP 2025

Larger models often outperform smaller ones but come with high computational costs. Cascading offers a potential solution. By default, it uses smaller models and defers only some instances to larger, more powerful models. However, designing effective deferral rules remains a challenge. In this paper

Cited by 0SourcePDFScholar
2025

Watching the Watchers: Exposing Gender Disparities in Machine Translation Quality Estimation

ACL 2025long

Quality estimation (QE)—the automatic assessment of translation quality—has recently become crucial across several stages of the translation pipeline, from data curation to training and decoding. While QE metrics have been optimized to align with human judgments, whether they encode social biases ha…

2025

XAMPLER: Learning to Retrieve Cross-Lingual In-Context Examples

NAACL 2025findings

Recent studies indicate that leveraging off-the-shelf or fine-tuned retrievers, capable of retrieving relevant in-context examples tailored to the input query, enhances few-shot in-context learning of English. However, adapting these methods to other languages, especially low-resource ones, poses ch…

2024

Analyzing Context Contributions in LLM-based Machine Translation

EMNLP 2024finding

Large language models (LLMs) have achieved state-of-the-art performance in machine translation (MT) and demonstrated the ability to leverage in-context learning through few-shot examples. However, the mechanisms by which LLMs use different parts of the input context remain largely unexplored. In thi…

2024

Can Automatic Metrics Assess High-Quality Translations?

EMNLP 2024main

Automatic metrics for evaluating translation quality are typically validated by measuring how well they correlate with human assessments. However, correlation methods tend to capture only the ability of metrics to differentiate between good and bad source-translation pairs, overlooking their reliabi…

2024

Modeling User Preferences with Automatic Metrics: Creating a High-Quality Preference Dataset for Machine Translation

EMNLP 2024main

Alignment with human preferences is an important step in developing accurate and safe large language models. This is no exception in machine translation (MT), where better handling of language nuances and context-specific variations leads to improved quality. However, preference data based on human…

2024

Non-Exchangeable Conformal Risk Control

ICLR 2024poster

Split conformal prediction has recently sparked great interest due to its ability to provide formally guaranteed uncertainty sets or intervals for predictions made by black-box neural models, ensuring a predefined probability of containing the actual ground truth. While the original formulation assu…

2024

QUEST: Quality-Aware Metropolis-Hastings Sampling for Machine Translation

NeurIPS 2024poster

An important challenge in machine translation (MT) is to generate high-quality and diverse translations. Prior work has shown that the estimated likelihood from the MT model correlates poorly with translation quality. In contrast, quality evaluation metrics (such as COMET or BLEURT) exhibit high c…

2024

Reranking Laws for Language Generation: A Communication-Theoretic Perspective

NeurIPS 2024spotlight

To ensure large language models (LLMs) are used safely, one must reduce their propensity to hallucinate or to generate unacceptable answers. A simple and often used strategy is to first let the LLM generate multiple hypotheses and then employ a reranker to choose the best one. In this paper, we draw…

Cited by 1SourcePDFScholar
2024

Sparse and Structured Hopfield Networks

ICML 2024spotlight

Modern Hopfield networks have enjoyed recent interest due to their connection to attention in transformers. Our paper provides a unified framework for sparse Hopfield networks by establishing a link with Fenchel-Young losses. The result is a new family of Hopfield-Fenchel-Young energies whose update…

2024

xTower: A Multilingual LLM for Explaining and Correcting Translation Errors

EMNLP 2024finding

While machine translation (MT) systems are achieving increasingly strong performance on benchmarks, they often produce translations with errors and anomalies. Understanding these errors can potentially help improve the translation quality and user experience. This paper introduces xTower, an open la…

Cited by 5SourcePDFScholar
2023

An Empirical Study of Translation Hypothesis Ensembling with Large Language Models

EMNLP 2023long main

Large language models (LLMs) are becoming a one-fits-many solution, but they sometimes hallucinate or produce unreliable output. In this paper, we investigate how hypothesis ensembling can improve the quality of the generated text for the specific problem of LLM-based machine translation. We experim…

Cited by 0SourcecodeScholar
2023

Steering Large Language Models for Machine Translation with Finetuning and In-Context Learning

EMNLP 2023short findings

Large language models (LLMs) are a promising avenue for machine translation (MT). However, current LLM-based MT systems are brittle: their effectiveness highly depends on the choice of few-shot examples and they often require extra post-processing due to overgeneration. Alternatives such as finetun…

Cited by 0SourceScholar
2022

Learning to Scaffold: Optimizing Model Explanations for Teaching

NeurIPS 2022accept

Modern machine learning models are opaque, and as a result there is a burgeoning academic subfield on methods that explain these models' behavior. However, what is the precise goal of providing such explanations, and how can we demonstrate that explanations achieve this goal? Some research argues t…

2022

Modeling Structure with Undirected Neural Networks

ICML 2022spotlight

Neural networks are powerful function estimators, leading to their status as a paradigm of choice for modeling structured data. However, unlike other structured representations that emphasize the modularity of the problem {–} e.g., factor graphs {–} neural networks are usually monolithic mappings fr…

2022

Quality-Aware Decoding for Neural Machine Translation

NAACL 2022long

Despite the progress in machine translation quality estimation and evaluation in the last years, decoding in neural machine translation (NMT) is mostly oblivious to this and centers around finding the most probable translation according to the model (MAP decoding), approximated with beam search. In…

2020

LP-SparseMAP: Differentiable Relaxed Optimization for Sparse Structured Prediction

ICML 2020poster

Structured predictors require solving a combinatorial optimization problem over a large number of structures, such as dependency trees or alignments. When embedded as structured hidden layers in a neural net, argmin differentiation and efficient gradient computation are further required. Recently, S…

2019

Learning Classifiers with Fenchel-Young Losses: Generalized Entropies, Margins, and Algorithms

AISTATS 2019poster

This paper studies Fenchel-Young losses, a generic way to construct convex loss functions from a regularization function. We analyze their properties in depth, showing that they unify many well-known loss functions and allow to create useful new ones easily. Fenchel-Young losses constructed from a…

Cited by 53SourcePDFScholar
2018

SparseMAP: Differentiable Sparse Structured Inference

ICML 2018oral

Structured prediction requires searching over a combinatorial number of structures. To tackle it, we introduce SparseMAP, a new method for sparse structured inference, together with corresponding loss functions. SparseMAP inference is able to automatically select only a few global structures: it is…

2016

From Softmax to Sparsemax: A Sparse Model of Attention and Multi-Label Classification

ICML 2016poster

We propose sparsemax, a new activation function similar to the traditional softmax, but able to output sparse probabilities. After deriving its properties, we show how its Jacobian can be efficiently computed, enabling its use in a network trained with backpropagation. Then, we propose a new smooth…

Cited by 974SourcePDFScholar