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.
Mentions as a table
| Chapter | Mentions | Cross-referenced |
|---|---|---|
| 00 Preface | 0 | No |
| 01 Definition | 0 | No |
| 02 Why Now | 0 | No |
| 03 Values & Principles | 0 | No |
| 04 The Stack | 0 | No |
| 05 Patterns | 0 | No |
| 06 The Role | 0 | No |
| 07 Maturity Model | 0 | No |
| 08 Regulatory Map | 0 | No |
| 10 Reading List | 0 | No |
| 11 AI Defined | 0 | No |
| 12 Governance Program | 0 | No |
| 13 Risk Management | 0 | No |
| 14 Development | 0 | No |
| 15 Deployment | 0 | No |
| 16 Fairness & XAI | 0 | No |
| 17 Incidents | 0 | No |
| 18 EU AI Act | 0 | No |
| 19 Privacy & AI | 0 | No |
| 20 Existing Law | 5 | Yes |
| 21 AI Laws Worldwide | 0 | No |
| 22 Principles & Standards | 0 | No |
| 23 AI Agents | 0 | No |
- 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 .