Contract Interpretation with Corpus Linguistics

61 Pages Posted: 8 Nov 2017 Last revised: 25 Nov 2018

See all articles by Stephen C. Mouritsen

Stephen C. Mouritsen

University of Chicago - Law School; Brigham Young University - J. Reuben Clark Law School

Date Written: August 27, 2018


When called upon to interpret the undefined language of a contract, judges and lawyers have for centuries appealed to the so-called Plain Meaning Rule — a canon of contractual interpretation that states that if the language of the contract is clear and unambiguous, courts cannot consider extrinsic evidence.

Courts and scholars disagree about the quantum of evidence that is necessary to determine the meaning of contractual provisions. Even absent a finding of ambiguity, contextualists look to extrinsic evidence to support claims about contractual meaning. But the contextualist approach may impose significant costs on the contracting parties and invite strategic behavior. Formalists, by contrast, justify the Plain Meaning Rule on the grounds of efficiency and predictability, and exclude extrinsic evidence absent a finding of ambiguity. But the formalist approach is faulted for failing to provide a meaningful account of the parties’ intentions and for placing heavy reliance upon the judge’s own linguistic intuitions and general-use English dictionaries — both problematic guides to Plain Meaning.

Corpus linguistics offers a middle way. Corpus linguistics draws on evidence of language use from large, coded, electronic collections of natural texts. Linguistic corpora can be designed to model the linguistic conventions of a wide variety of speech communities, industries, or linguistic registers. Relying on language evidence from linguistic corpora, judges and lawyers can create a more accurate, evidence-based picture of the language use of the contracting parties. Because large, sophisticated linguistic corpora are freely available and easy to use with a modicum of training, language evidence from linguistic corpora offers a comparatively low-cost alternative to the vast quantity of extrinsic evidence permitted by contextualist interpretive approaches. Moreover, by evaluating corpus evidence, judges and lawyers can create a more accurate, objective picture of contractual meaning than can be found in the formalist judge’s linguistic intuition or in a general-use dictionary.

At bottom, I argue that corpora can provide objective evidence of the linguistic conventions of the communities that draft and are governed by the agreements judges and lawyers are called upon to interpret. Corpus evidence can give content to otherwise vague canons of interpretation and provide linguistic evidence to aid in the evaluation of claims about the Plain Meaning (or ambiguity) of a contractual text. Below I outline how corpus linguistic methods may be applied to the interpretation of contracts.

Keywords: corpus linguistics, contracts, interpretation, plain meaning, ordinary meaning, ambiguity

Suggested Citation

Mouritsen, Stephen C., Contract Interpretation with Corpus Linguistics (August 27, 2018). Washington Law Review, Vol. 94, No. __, (2019 Forthcoming). Available at SSRN: or

Stephen C. Mouritsen (Contact Author)

University of Chicago - Law School ( email )

1111 E. 60th St.
Chicago, IL 60637
United States

Brigham Young University - J. Reuben Clark Law School ( email )

430 JRCB
Brigham Young University
Provo, UT 84602
United States

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