The US copyright defence that weighs four factors: purpose and transformativeness, nature of the work, amount used and market effect 1. Courts apply it to AI training case by case; results so far turn on how the data was acquired and on each record.
- Developed in
- ch. 20, US training cases, dated
- Chapters
- ch. 20, Existing Law
- Contrast with
- TDM exception
- Source
- 1 numbered reference, listed below
Where it is used
One chapter of the Body of Knowledge uses the term. Each link opens the first section that does.
- 20 · Existing Law Intellectual property 5 mentions
Sources
- [1] 17 U.S.C. § 107, Limitations on exclusive rights: fair use (the four factors). Legal Information Institute, Cornell Law School. 2026. https://www.law.cornell.edu/uscode/text/17/107 (verified: secondary)
Definitions of legal terms paraphrase the cited text, which governs. Dated statements are as of .