Abstract
This study examines the effectiveness of a WhatsApp-based mobile learning program for adult language learners in Padang City, Indonesia. Employing a mixed-method approach that integrates quantitative and qualitative analyses, the research investigates how multimedia integration through mobile platforms influences learners’ motivation and achievement within the framework of andragogy. A total of one hundred adult participants were divided into two groups: an experimental group engaged in WhatsApp-based learning and a control group receiving conventional classroom instruction. Quantitative results showed that learners in the WhatsApp group demonstrated significantly greater improvements in language proficiency, reading comprehension, and vocabulary development than the control group. Qualitative findings further underscored the flexibility, accessibility, and motivational appeal of WhatsApp as a learning platform, highlighting its capacity to support collaborative and self-directed learning. The study concludes that mobile learning, particularly through widely accessible applications like WhatsApp, can serve as an effective and inclusive medium for adult foreign language education. These findings enrich the growing body of research on mobile-assisted language learning (MALL) and offer practical insights for expanding educational opportunities among adult and underserved populations in developing contexts.