PeopleofSuperintelligence

Researcher

Timothy O'Donnell

Also known as Timothy J. O'Donnell

Timothy O'Donnell is a computational linguist whose AI research studies how people learn and process language. He earned a PhD from Harvard, developed Fragment Grammars for language productivity, and presented that work in his 2015 book, Productivity and Reuse in Language: A Theory of Linguistic Computation and Storage. At McGill, he was an investigator on a project about robust unsupervised language learning and coauthored a 2022 system for building interpretable models of human language. His 2025 papers examined causal relations among word patterns and ways to convert token-level language models into character-level models. As of October 2026, he is an associate professor of linguistics at McGill, a Canada CIFAR AI Chair at Mila.

Works
139
Citations
1,823
h-index
18

Publication numbers from OpenAlex, as of 27 October 2026.

Timeline

  1. 2011

    Fragment Grammars

    In 2011, his Harvard psychology dissertation develops Fragment Grammars, a Bayesian model of language productivity and reuse. He holds a PhD from Harvard University.

  2. 2015

    Productivity and Reuse in Language

    In 2015, he publishes Productivity and Reuse in Language: A Theory of Linguistic Computation and Storage, presenting that work in book form.

  3. 2018–2022

    Unsupervised language learning

    From 2018 to 2022, he is the investigator for McGill’s NSERC Discovery project Towards Robust Unsupervised Language Learning. The project aims to build systems that generalize in human-like ways through theoretical linguistics and probabilistic models.

  4. 2019

    A Canada CIFAR AI Chair

    In 2019, he is named among six new Canada CIFAR AI Chairs affiliated with McGill’s School of Computer Science.

  5. 2022

    A Bayesian language system

    In 2022, he coauthors Synthesizing theories of human language with Bayesian program induction. The framework combines Bayesian inference and program synthesis to build human-interpretable models across 70 datasets from 58 languages.

  6. 2025

    Causal discovery across languages

    In 2025, he coauthors Unzipping the Causality of Zipf’s Law and Other Lexical Trade-offs. The paper applies causal discovery to word length, frequency, phonotactic complexity, and morphological irregularity across 25 languages.

  7. 2025

    Character-level language models

    In 2025, he coauthors From Language Models over Tokens to Language Models over Characters, which presents exact and approximate algorithms for converting token-level models into character-level models.

  8. As of October 2026

    McGill associate professor

    As of October 2026, he is an associate professor in McGill’s Department of Linguistics, a Canada CIFAR AI Chair at Mila. His expertise covers computational models of language learning and processing, mathematical linguistics, and probabilistic inference.

Career

  1. NowMcGill UniversityAssociate Professor
  2. NowMilaCanada CIFAR AI Chair

Education

  1. 2011Harvard UniversityPhD

From the biography.

Sources and credits

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  1. Productivity and Reuse in Language - McGill NLP mcgill-nlp.github.io. Checked 27 October 2026.
  2. Timothy O'Donnell | Linguistics - McGill University mcgill.ca. Checked 27 October 2026.
  3. CiNii 図書 - Productivity and reuse in language : a theory of linguistic computation and storage ci.nii.ac.jp. Checked 27 October 2026.
  4. Projects & Grants | Linguistics - McGill University mcgill.ca. Checked 27 October 2026.
  5. Announcement of New Canada CIFAR AI Chairs cs.mcgill.ca. Checked 27 October 2026.
  6. Synthesizing theories of human language with Bayesian program induction | Nature Communications nature.com. Checked 27 October 2026.
  7. Unzipping the Causality of Zipf’s Law and Other Lexical Trade-offs - ACL Anthology aclanthology.org. Checked 27 October 2026.
  8. From Language Models over Tokens to Language Models over Characters - Proceedings of Machine Learning Research proceedings.mlr.press. Checked 27 October 2026.
  9. People | Linguistics - McGill University mcgill.ca. Checked 27 October 2026.