The Measurement Gap in the Automation of EU Law: Benchmarking Doctrinal Legal Reasoning under the EU AI Act

2026-06-16

AI Summary

Current evaluations of legal AI systems are largely confined to auxiliary tasks and fail to adequately assess doctrinal legal reasoning, leaving the European Union’s Artificial Intelligence Act’s requirement of “appropriate accuracy” without operationalizable standards. This study introduces the first benchmark specifically designed for evaluating doctrinal legal reasoning, translating regulatory compliance demands into technically measurable indicators. By integrating legal doctrinal analysis with large language model evaluation methodologies, the work formulates specialized tasks to assess capabilities in legal interpretation and reasoning. The proposed framework addresses a critical gap in evaluating high-risk judicial AI systems at the level of professional legal reasoning, thereby providing essential support for advancing legal AI beyond mere text generation toward normatively compliant, expert-level reasoning.

Abstract

Large language models now produce legal text of at least median quality, yet no existing benchmark can evaluate whether they perform doctrinal legal reasoning, which forms the interpretive core of legal work, rather than the ancillary, paralegal tasks that most current legal-AI evaluations measure. This measurement gap is not only methodological but legal: the EU AI Act makes "appropriate accuracy" a binding requirement for high-risk AI used in the judicial domain, yet that requirement cannot acquire operational content without the very doctrinal-reasoning benchmark the field lacks.

Problem

• doctrinal legal reasoning
• EU AI Act
• benchmarking
• measurement gap
• legal AI

Innovation

• doctrinal legal reasoning
• EU AI Act
• legal benchmarking
• measurement gap
• high-risk AI