This research investigates the use of Data-driven learning (DDL) tasks in the teaching and learning of acronyms in a specialised corpus. Our target population is professional military staff (n=16). The researchers collected and analysed the Salvage and Rescue of Submarines Corpus (SAR) where the patterning of acronyms, neglected in English for Specific Purposes (ESP), plays a substantial role. Using a mixed-methods methodology, this research looked at the students’ interaction with DDL, as well as at the subsequent interviews with the students. Deductive and inductive paper-based DDL tasks with concordance lines of acronyms were used with two groups of students of different rank. Both groups found the tasks challenging and showed mixed reactions towards concordance lines. While there has been a much-needed emphasis on tools and corpus methods training in DDL, we suggest that conversations with adult, professional students about the nature of instructed language learning and language patterning are absolutely essential to promote a more active learner role in DDL approaches.