Adapters for Altering LLM Vocabularies: What Languages Benefit the Most?
Not on the map. Why?
Abstract (arXiv)
Vocabulary adaptation, which integrates new vocabulary into pre-trained language models, enables expansion to new languages and mitigates token over-fragmentation. However, existing approaches are limited by their reliance on heuristics or external embeddings. We propose VocADT, a novel method for vocabulary adaptation using adapter modules that are trained to learn the optimal linear combination of existing embeddings while keeping the model's weights fixed. VocADT offers a flexible and scalable solution without depending on external resources or language constraints. Across 11 languages-with diverse scripts, resource availability, and fragmentation-we demonstrate that VocADT outperforms the original Mistral model and other baselines across various multilingual tasks including natural language understanding and machine translation. We find that Latin-script languages and highly fragmented languages benefit the most from vocabulary adaptation. We further fine-tune the adapted model on the generative task of machine translation and find that vocabulary adaptation is still beneficial after fine-tuning and that VocADT is the most effective.
Key facts. Cited by 9 papers in the map (data through 7 Oct 2026). Builds on 58 of its 76 references that are in the map. First posted on arXiv 12 Oct 2024.
Builds on
58 of 76 references.
References · 58
- 2020Measuring Massive Multitask Language Understandingcited by 7,768
- 2019BERTScore: Evaluating Text Generation with BERTcited by 5,462
- 2016Overcoming catastrophic forgetting in neural networkscited by 4,718
- 2019Parameter-Efficient Transfer Learning for NLPcited by 4,195
- 2018SentencePiece: A simple and language independent subword tokenizer and detokenizer for Neural Text Processingcited by 1,973
- 2022No Language Left Behind: Scaling Human-Centered Machine Translationcited by 1,290
- 2020BLEURT: Learning Robust Metrics for Text Generationcited by 1,196
- 2020COMET: A Neural Framework for MT Evaluationcited by 1,024
- 2018XNLI: Evaluating Cross-lingual Sentence Representationscited by 913
- 2020The State and Fate of Linguistic Diversity and Inclusion in the NLP Worldcited by 789
- 2021The FLORES-101 Evaluation Benchmark for Low-Resource and Multilingual Machine Translationcited by 556
- 2021Documenting Large Webtext Corpora: A Case Study on the Colossal Clean Crawled Corpuscited by 481
38 more
- 2020MAD-X: An Adapter-Based Framework for Multi-Task Cross-Lingual Transfercited by 443
- 2018Massively Multilingual Sentence Embeddings for Zero-Shot Cross-Lingual Transfer and Beyondcited by 434
- 2020XCOPA: A Multilingual Dataset for Causal Commonsense Reasoningcited by 330
- 2023The Belebele Benchmark: a Parallel Reading Comprehension Dataset in 122 Language Variantscited by 300
- 2024Aya Model: An Instruction Finetuned Open-Access Multilingual Language Modelcited by 292
- 2023xCOMET: Transparent Machine Translation Evaluation through Fine-grained Error Detectioncited by 260
- 2019Massively Multilingual Neural Machine Translationcited by 246
- 2021Quality at a Glance: An Audit of Web-Crawled Multilingual Datasetscited by 241
- 2019WikiMatrix: Mining 135M Parallel Sentences in 1620 Language Pairs from Wikipediacited by 221
- 2023Language Model Tokenizers Introduce Unfairness Between Languagescited by 207
- 2023Okapi: Instruction-tuned Large Language Models in Multiple Languages with Reinforcement Learning from Human Feedbackcited by 189
- 2023Do All Languages Cost the Same? Tokenization in the Era of Commercial Language Modelscited by 186
- 2019CCMatrix: Mining Billions of High-Quality Parallel Sentences on the WEBcited by 177
- 2020Automatic Machine Translation Evaluation in Many Languages via Zero-Shot Paraphrasingcited by 114
- 2021WECHSEL: Effective initialization of subword embeddings for cross-lingual transfer of monolingual language modelscited by 89
- 2020Extending Multilingual BERT to Low-Resource Languagescited by 88
- 2023A Paradigm Shift in Machine Translation: Boosting Translation Performance of Large Language Modelscited by 88
- 2023Large language models effectively leverage document-level context for literary translation, but critical errors persistcited by 80
- 2018On the Impact of Various Types of Noise on Neural Machine Translationcited by 76
- 2020Language ID in the Wild: Unexpected Challenges on the Path to a Thousand-Language Web Text Corpuscited by 76
- 2021A Statistical Analysis of Summarization Evaluation Metrics using Resampling Methodscited by 71
- 2022Embarrassingly Easy Document-Level MT Metrics: How to Convert Any Pretrained Metric Into a Document-Level Metriccited by 56
- 2020Improving Multilingual Models with Language-Clustered Vocabulariescited by 53
- 2022Bitext Mining Using Distilled Sentence Representations for Low-Resource Languagescited by 48
- 2024Fast Vocabulary Transfer for Language Model Compressioncited by 42
- 2020From English To Foreign Languages: Transferring Pre-trained Language Modelscited by 37
- 2023OFA: A Framework of Initializing Unseen Subword Embeddings for Efficient Large-scale Multilingual Continued Pretrainingcited by 37
- 2020Paraphrase Generation as Zero-Shot Multilingual Translation: Disentangling Semantic Similarity from Lexical and Syntactic Diversitycited by 35
- 2024A Shocking Amount of the Web is Machine Translated: Insights from Multi-Way Parallelismcited by 33
- 2024Zero-Shot Tokenizer Transfercited by 30
- 2017Regularization techniques for fine-tuning in neural machine translationcited by 27
- 2023Efficient Language Model Training through Cross-Lingual and Progressive Transfer Learningcited by 26
- 2019Low-Resource Corpus Filtering using Multilingual Sentence Embeddingscited by 25
- 2024Improving Statistical Significance in Human Evaluation of Automatic Metrics via Soft Pairwise Accuracycited by 25
- 2024Fine-Tuned Machine Translation Metrics Struggle in Unseen Domainscited by 21
- 2024An Empirical Comparison of Vocabulary Expansion and Initialization Approaches for Language Modelscited by 20
- 2018Compact Personalized Models for Neural Machine Translationcited by 19
- 2024An Empirical Study on Cross-lingual Vocabulary Adaptation for Efficient Language Model Inferencecited by 18
50 most cited of 58 All 58 (JSON)
Built on by
Citing papers per year: 2024: 1; 2025: 4; 2026: 4.
9 papers.
- 2025Crosslingual Reasoning through Test-Time Scalingcited by 46
- 2025Continually Adding New Languages to Multilingual Language Modelscited by 7
- 2024Adapting Chat Language Models Using Only Target Unlabeled Language Datacited by 6
- 2025Dictionaries to the Rescue: Cross-Lingual Vocabulary Transfer for Low-Resource Languages Using Bilingual Dictionariescited by 2
- 2026From Token to Token Pair: Efficient Prompt Compression for Large Language Models in Clinical Predictioncited by 2
- 2025Vocab Diet: Reshaping the Vocabulary of LLMs via Vector Arithmeticcited by 1
- 2026Understanding Secret Leakage Risks in Code LLMs: A Tokenization Perspectivecited by 0
- 2026HiMed: Incentivizing Hindi Reasoning in Medical LLMscited by 0
- 2026Different Perturbations, Different Mechanisms: Understanding Continued Pre-training for Zero-Shot Dialect Robustnesscited by 0
- 2026Different Perturbations, Different Mechanisms: Understanding Continued Pre-training for Zero-Shot Dialect Robustness6 Aug 2026
- 2026HiMed: Incentivizing Hindi Reasoning in Medical LLMs23 May 2026
- 2026From Token to Token Pair: Efficient Prompt Compression for Large Language Models in Clinical Prediction12 May 2026
- 2026Understanding Secret Leakage Risks in Code LLMs: A Tokenization Perspective20 Apr 2026
- 2025Vocab Diet: Reshaping the Vocabulary of LLMs via Vector Arithmetic19 Oct 2025
- 2025Continually Adding New Languages to Multilingual Language Models14 Sep 2025
- 2025Dictionaries to the Rescue: Cross-Lingual Vocabulary Transfer for Low-Resource Languages Using Bilingual Dictionaries2 Jun 2025
- 2025Crosslingual Reasoning through Test-Time Scaling8 May 2025
- 2024Adapting Chat Language Models Using Only Target Unlabeled Language Data16 Dec 2024