The King Saud bin Abdulaziz University for Health Sciences Learner Corpus: A Longitudinal Resource for Researching the Development of Academic Writing Proficiency in EFL Learners

Abstract The King Saud bin Abdulaziz University for Health Sciences (KSAUHS) Learner Corpus is a new longitudinal corpus of English as a Foreign Language (EFL) academic writing at the university level that complies with the FAIR principles. Collection began in 2022, the corpus captures writing development during a period of emerging language technologies. The corpus currently contains over a million words from 158 learners across four proficiency levels (CEFR A1-B2). Texts span four trimesters and multiple academic genres, including paragraphs and essays in rhetorical modes like cause-effect, argumentation, and summarization. Metadata includes learners' parents’ first language background, other foreign languages, academic focus, and reference tool preferences. The corpus enables research into multiple dimensions of second language writing development to inform EAP pedagogy and assessment. Avenues for investigation include: lexico-grammatical development, cross-linguistic influence, individual differences, instructional interventions, impacts of task conditions and language technologies, and longitudinal trajectories. Ongoing corpus expansion aims to expand size, representation, and accessibility. This unique resource promises data-driven insights into the textual features and factors that characterize and facilitate intermediate and advanced EFL writing proficiency in university contexts.