Controlled Language Increases Comprehension of Law for People

Clement Guitton, Aurelia Tamò-Larrieux, Simon Mayer, Lukas Zumbrunn

Abstract: Law is written in a way that is not easily understandable by most people. This also hinders the translation into computer code, which would permit the creation of tools that increase access to the law. The use of controlled language in legal texts is a promising way to implement laws that are better comprehensible by people, and computer-executable at the same time. However, while the scholarship on controlled language has been concentrating on its translation into (logic) programs, the effects on people have not been investigated. We conducted an experiment to test the understandability, usability, and perceived open-texture (e.g., ambiguity, vagueness) of legal texts that are formulated in natural language and in controlled language. Among our 73 participants—including members of parliament (MPs) and public servants—we found that the use of controlled language increases understandability across legal domains but does not reduce the number of terms that are perceived as open-texture. We also found that public servants show higher comprehension of legal statutes but lower perception of open-texture than MPs, regardless of whether these are in controlled or natural language. We conclude that controlled language can therefore support a wider access to law, thereby bringing democratic societies closer to their underpinning ideals and principles.

External IDs:dblp:journals/acmjcss/GuittonTMZ25