Challenge: Large Language Models fail at simple character-level tasks due to low mutual information, study finds . authors propose a lightweight architectural modification that improves character- level reasoning .
Approach: They propose a lightweight architectural modification that improves character-level reasoning while preserving the inductive advantages of subword models.
Outcome: The proposed model improves character-level reasoning while preserving the advantages of subword models.

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Challenge: Pre-trained language models that use subword tokenization schemes can succeed at a variety of language tasks that require character-level information.
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How Do Language Models Acquire Character-Level Information? (2026.eacl-long)

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Challenge: Language models (LMs) implicitly encode character-level information, despite not being explicitly provided during training.
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How Tokenization Limits Phonological Knowledge Representation in Language Models and How to Improve Them (2026.acl-long)

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Challenge: Tokenization is the first step in every language model (LM), yet it never takes the sounds of words into account.
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Learn Your Tokens: Word-Pooled Tokenization for Language Modeling (2023.findings-emnlp)

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Challenge: Language models typically tokenize text into subwords, using a deterministic, hand-engineered heuristic of combining characters into longer surface-level strings such as ‘ing’ or whole words.
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Tokenization Falling Short: On Subword Robustness in Large Language Models (2024.findings-emnlp)

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Challenge: Language models typically tokenize raw text into sequences of subword identifiers from a predefined vocabulary.
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Spelling-out is not Straightforward: LLMs’ Capability of Tokenization from Token to Characters (2025.findings-emnlp)

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Challenge: Large language models (LLMs) can spell out tokens character by character with high accuracy, yet struggle with more complex character-level tasks.
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Token Knowledge: A New Perspective For Knowledge in Large Language Models (2025.findings-emnlp)

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Challenge: Predicting the presence and absence of certain knowledge in large language models could aid hallucination avoidance.
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Small Language Models Also Work With Small Vocabularies: Probing the Linguistic Abilities of Grapheme- and Phoneme-Based Baby Llamas (2025.coling-main)

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Challenge: Existing studies on LMs have focused on linguistic generalizations and representations from developmentally plausible data.
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SubTokenTest: A Practical Benchmark for Real-World Sub-token Understanding (2026.acl-long)

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Challenge: Existing benchmarks have highlighted character-level tasks as lacking practical relevance . many real-world applications rely heavily on precise sub-token understanding .
Approach: They propose a benchmark that assesses sub-token understanding through practical tasks . they examine the impact of test-time scaling on sub-word reasoning .
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From Characters to Words: Hierarchical Pre-trained Language Model for Open-vocabulary Language Understanding (2023.acl-long)

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Challenge: Current models for natural language understanding require a preprocessing step to convert raw text into discrete tokens.
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