斯坦福大学法学院研究：人工智能的表现优于法学教授

A groundbreaking study led by Stanford Law School Professor Julian Nyarko reveals that law professors overwhelmingly prefer AI-generated answers to student questions over responses written by their fellow instructors—a finding that could reshape how legal education is delivered.

The study, titled “Law Professors Prefer AI Over Peer Answers,” was conducted with 16 law professors across U.S. law schools and tested whether large language models could serve as effective tutors for contract law courses.In a blind evaluation of nearly 3,000 anonymized comparisons, professors rated AI responses significantly higher than answers written by other professors, with AI winning 75% of head-to-head matchups.

“This study challenges important assumptions about AI’s role in legal education,” said Nyarko, who leads Stanford Law School’s Legal Innovation through Frontier Technology Lab, or liftlab. He co-authored the paper with colleagues from Yale, NYU, University of Chicago, and other leading institutions. “We focused on law precisely because it requires judgment, nuanced reasoning, and the ability to navigate ambiguity—not just factual recall.”

#### Can LLMs Reason?

The study is particularly notable because previous AI evaluations have focused primarily on subjects with clear right-or-wrong answers. Legal reasoning, by contrast, demands careful analysis of competing arguments and defensible conclusions.

Stanford Law Professor Julian Nyarko

“We were frankly surprised by the magnitude of the results,” Nyarko added. “These weren’t just simple questions with obvious answers. Many of them required synthesizing complex material, applying it to new situations, and explaining legal concepts in ways that would help students develop their own analytical skills.”

Participants created 40 representative contracts law questions that students might ask after class or during office hours, wrote their own answers, and then evaluated responses without knowing whether they came from AI or other participating professors. The AI systems performed comparably to the best human instructor in the study.

Perhaps most striking: professors flagged AI responses as pedagogically harmful only 3.5% of the time, compared to 12% for peer-written answers.

“In most fields where AI gets tested, there’s a right answer. In law, there often isn’t.” said Sarath Sanga, co-author and professor at Yale Law School. “Two opposing arguments can both be good. What we wanted to know is whether AI can meet the latent professional standard that lawyers use to evaluate each other’s arguments. In this case, the answer was yes.”

The research team took extensive precautions to ensure the study’s validity. They calibrated AI responses to match the length and structure of human answers, used multiple evaluation methods, and had professors assess whether responses might mislead or confuse students.

#### Transforming Legal Education

“We designed this study to be as rigorous as possible because the stakes are so high,” Nyarko explained. “Legal education is about training future lawyers to think critically, argue persuasively, and navigate ethical complexities. Our study makes important steps towards finding out whether AI could support that mission.”

Alejandro Salinas, first author of the study and a researcher at Nyarko’s liftlab, emphasized the educational implications: “Our study shifts attention to what AI tutoring can contribute to learning in judgment-rich fields like law. We find that, when evaluated by legal educators, AI tutors can offer high-quality, on-demand support that complements classroom instruction, and may broaden access to expert guidance.”

The study also examined specific AI models, including commercial tutoring systems and Google’s NotebookLM, finding varying levels of performance. However, even when context limitations affected AI responses, professors still frequently preferred them to human-written alternatives.

The findings arrive as law schools nationwide grapple with integrating AI tools into legal education while maintaining rigorous academic standards. Some institutions have embraced AI experimentation, while others remain cautious about potential risks including hallucinations, overreliance, and the erosion of critical thinking skills.

“Our study evaluates the quality of answers given by AI tools. But how to implement these tools to most effectively improve student learning is still an open question. So we’re not advocating for wholesale adoption of AI tutors,” Nyarko cautioned. “But our data suggests that blanket skepticism may be equally unwarranted. The conversation should shift from whether AI can give accurate, high quality responses to how we can deploy it responsibly to the benefit of our students.”

View the Publication

Link to SSRN

#### About liftlab

Liftlab is among the first academic efforts in legal AI to unite research, prototyping, and real-time collaboration with industry. Its mission is to increase access to high quality legal services in the private sector by leveraging AI and other frontier technologies. To bridge the gap between theory and practice, liftlab’s work extends beyond conceptualization and encompasses the building of prototypes that help explore the utility of AI-based solutions.

#### About Stanford Law School

Stanford Law School is one of the world’s leading institutions for legal scholarship and education. Its alumni are among the most influential decision makers in law, politics, business, and high technology. Faculty members argue before the Supreme Court, testify before Congress, produce outstanding legal scholarship and empirical analysis, and contribute regularly to the nation’s press as legal and policy experts. Stanford Law School has established a model for legal education that provides rigorous interdisciplinary training, hands-on experience, global perspective and a focus on public service.