The KSAUHS learner corpus

Abstract The KSAU-HS Learner Corpus is a longitudinal corpus of EFL tertiary writing that complies with the FAIR principles. Collection began in 2022 and captures writing development during a period of emerging language technologies (2022–24). The corpus contains over 856,907 tokens across 2,387 texts produced by 157 preparatory year university students, within a CEFR-aligned program with an instructional range of approximately A2-B2. Texts span four trimesters and include rhetorical modes such as cause-and-effect, argumentation, and summarisation. Metadata includes years of English schooling, other languages spoken, and preferred reference tools. The corpus enables research into writing development to inform EAP pedagogy and assessment. Avenues for investigation include lexico-grammatical development, cross-linguistic influence, individual differences, and the impact of task conditions and language technologies. This resource promises data-driven insights into the textual features and factors that characterise EFL writing proficiency, and plans are in place to expand its size, representation, and accessibility.