Bagdasarov, Sergei; Degaetano-Ortlieb, Stefania

Applying Information-theoretic Notions to Measure Effects of the Plain English Movement on English Law Reports and Scientific Articles

Bizzoni, Yuri; Degaetano-Ortlieb, Stefania; Kazantseva, Anna; Szpakowicz, Stan (Ed.): Proceedings of the 8th Joint SIGHUM Workshop on Computational Linguistics for Cultural Heritage, Social Sciences, Humanities and Literature (LaTeCH-CLfL 2024), Association for Computational Linguistics, pp. 101-110, St. Julians, Malta, 2024.

We investigate the impact of the Plain English Movement (PEM) on the complexity of legal language in UK law reports from the 1950s-2010s, contrasting it with the evolution of scientific language. The PEM, emerging in the late 20th century, advocated for clear and understandable legal language. We define complexity through the concept of surprisal – an information-theoretic measure correlating with cognitive processing difficulty. Our research contrasts surprisal with traditional readability measures, which often overlook content. We hypothesize that, if the PEM has influenced legal language, there would be a reduction in complexity over time and a shift from a nominal to a more verbal style. We analyze text complexity and lexico-grammatical changes in line with PEM recommendations. Results indicate minimal impact of the PEM on both legal and scientific domains. This finding suggests future research should consider processing effort when advocating for linguistic norms to enhance accessibility.