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Valentin Hofmann

19 accepted papers

2026

Can Large Language Models Generalize Procedures Across Representations?

ICML 2026poster

Large language models (LLMs) are trained and tested extensively on symbolic representations such as code and graphs, yet real-world user tasks are often specified in natural language. To what extent can LLMs generalize across these representations? Here, we approach this question by studying isomorp…

Cited by 0SourceScholar
2025

Aligned but Blind: Alignment Increases Implicit Bias by Reducing Awareness of Race

ACL 2025long

Although value-aligned language models (LMs) appear unbiased in explicit bias evaluations, they often exhibit stereotypes in implicit word association tasks, raising concerns about their fair usage. We investigate the mechanisms behind this discrepancy and find that alignment surprisingly amplifies…

2025

Assessing Dialect Fairness and Robustness of Large Language Models in Reasoning Tasks

ACL 2025long

Language is not monolithic. While benchmarks, including those designed for multiple languages, are often used as proxies to evaluate the performance of Large Language Models (LLMs), they tend to overlook the nuances of within-language variation and thus fail to model the experience of speakers of no…

Cited by 0SourcePDFScholar
2025

Large Language Models Discriminate Against Speakers of German Dialects

EMNLP 2025

Dialects represent a significant component of human culture and are found across all regions of the world. In Germany, more than 40% of the population speaks a regional dialect (Adler and Hansen, 2022). However, despite cultural importance, individuals speaking dialects often face negative societal

Cited by 0SourcePDFScholar
2025

Measuring what Matters: Construct Validity in Large Language Model Benchmarks

NeurIPS 2025poster

Evaluating large language models (LLMs) is crucial for both assessing their capabilities and identifying safety or robustness issues prior to deployment. Reliably measuring abstract and complex phenomena such as `safety' and `robustness' requires strong construct validity, that is, having measures t…

Cited by 0SourceScholar
2025

Signal and Noise: A Framework for Reducing Uncertainty in Language Model Evaluation

NeurIPS 2025spotlight

Developing large language models is expensive and often involves making decisions with small experiments, typically by evaluating on large, multi-task evaluation suites. In this work, we analyze specific properties which make a benchmark more reliable and useful for such decisions, and interventions…

Cited by 0SourceScholar
2024

Dolma: an Open Corpus of Three Trillion Tokens for Language Model Pretraining Research

ACL 2024long

Information about pretraining corpora used to train the current best-performing language models is seldom discussed: commercial models rarely detail their data, and even open models are often released without accompanying training data or recipes to reproduce them. As a result, it is challenging to…

2024

Graph-enhanced Large Language Models in Asynchronous Plan Reasoning

ICML 2024poster

Planning is a fundamental property of human intelligence. Reasoning about asynchronous plans is challenging since it requires sequential and parallel planning to optimize time costs. Can large language models (LLMs) succeed at this task? Here, we present the first large-scale study investigating thi…

2024

MAGNET: Improving the Multilingual Fairness of Language Models with Adaptive Gradient-Based Tokenization

NeurIPS 2024poster

In multilingual settings, non-Latin scripts and low-resource languages are usually disadvantaged in terms of language models’ utility, efficiency, and cost. Specifically, previous studies have reported multiple modeling biases that the current tokenization algorithms introduce to non-Latin script la…

Cited by 4SourcePDFScholar
2024

Paloma: A Benchmark for Evaluating Language Model Fit

NeurIPS 2024poster

Evaluations of language models (LMs) commonly report perplexity on monolithic data held out from training. Implicitly or explicitly, this data is composed of domains—varying distributions of language. We introduce Perplexity Analysis for Language Model Assessment (Paloma), a benchmark to measure LM…

Cited by 7SourcePDFScholar
2024

Political Compass or Spinning Arrow? Towards More Meaningful Evaluations for Values and Opinions in Large Language Models

ACL 2024long

Much recent work seeks to evaluate values and opinions in large language models (LLMs) using multiple-choice surveys and questionnaires. Most of this work is motivated by concerns around real-world LLM applications. For example, politically-biased LLMs may subtly influence society when they are used…

2023

Counting the Bugs in ChatGPT's Wugs: A Multilingual Investigation into the Morphological Capabilities of a Large Language Model

EMNLP 2023long main

Large language models (LLMs) have recently reached an impressive level of linguistic capability, prompting comparisons with human language skills. However, there have been relatively few systematic inquiries into the linguistic capabilities of the latest generation of LLMs, and those studies that do…

Cited by 0SourceScholar
2022

An Embarrassingly Simple Method to Mitigate Undesirable Properties of Pretrained Language Model Tokenizers

ACL 2022short

We introduce FLOTA (Few Longest Token Approximation), a simple yet effective method to improve the tokenization of pretrained language models (PLMs). FLOTA uses the vocabulary of a standard tokenizer but tries to preserve the morphological structure of words during tokenization. We evaluate FLOTA on…

2022

CaMEL: Case Marker Extraction without Labels

ACL 2022long

We introduce CaMEL (Case Marker Extraction without Labels), a novel and challenging task in computational morphology that is especially relevant for low-resource languages. We propose a first model for CaMEL that uses a massively multilingual corpus to extract case markers in 83 languages based only…

2022

Modeling Ideological Salience and Framing in Polarized Online Groups with Graph Neural Networks and Structured Sparsity

NAACL 2022findings

The increasing polarization of online political discourse calls for computational tools that automatically detect and monitor ideological divides in social media. We introduce a minimally supervised method that leverages the network structure of online discussion forums, specifically Reddit, to dete…

2022

The better your Syntax, the better your Semantics? Probing Pretrained Language Models for the English Comparative Correlative

EMNLP 2022main

Construction Grammar (CxG) is a paradigm from cognitive linguistics emphasising the connection between syntax and semantics. Rather than rules that operate on lexical items, it posits constructions as the central building blocks of language, i.e., linguistic units of different granularity that combi…

Cited by 43SourcePDFScholar
2022

Unsupervised Detection of Contextualized Embedding Bias with Application to Ideology

ICML 2022spotlight

We propose a fully unsupervised method to detect bias in contextualized embeddings. The method leverages the assortative information latently encoded by social networks and combines orthogonality regularization, structured sparsity learning, and graph neural networks to find the embedding subspace c…

2021

Superbizarre Is Not Superb: Derivational Morphology Improves BERT’s Interpretation of Complex Words

ACL 2021long

How does the input segmentation of pretrained language models (PLMs) affect their interpretations of complex words? We present the first study investigating this question, taking BERT as the example PLM and focusing on its semantic representations of English derivatives. We show that PLMs can be int…