Stanford Study Finds AI Outperforms Law Professors in 75% of Blind Contract-Law Tests, but Humans Preferred in 25%

A blind study led by Stanford Law School professor Julian Nyarko found AI-generated responses selected over those written by law professors in 75% of nearly 3,000 head-to-head comparisons. Law professors at 16 schools evaluated anonymized answers to 40 contract law questions. The questions required synthesis of competing arguments and a defensible conclusion rather than rote recall.

5% of the time. They flagged peer-written answers as misleading or harmful 12% of the time. The paper was authored by Nyarko with liftlab researcher Alejandro Salinas as first author, alongside colleagues from Yale, New York University, the University of Chicago and other institutions.

Participants wrote their own answers before grading anyone else's. Evaluations ran blind through multiple scoring methods. AI outputs were calibrated to match the length and structure of human responses.

The team tested a range of systems, including commercial tutoring tools and Google's NotebookLM. Performance varied across systems. Nyarko directs Stanford's Legal Innovation through Frontier Technology Lab.

Nyarko said the conversation should now move from whether AI can produce accurate, high-quality legal answers to how it can best benefit students. The study was published Monday, June 2, 2026.