Enhancing Vocabulary Acquisition through Asynchronous Learning: The Use of YouTube Channels in Indonesian Secondary Classrooms

This study investigates the impact of asynchronous learning through YouTube on vocabulary acquisition among eleventh-grade students at SMK PN 2 Purworejo, Indonesia. Using a descriptive qualitative case study design, researchers collected data through pre- and post-tests, semi-structured interviews, and analysis of student engagement with the Vocab App-Learn English Words YouTube channel. Results indicate that integrating asynchronous multimedia content significantly improved students' vocabulary mastery, motivation, and engagement. Initial vocabulary test scores averaged 64, increasing to 76.75 after treatment. The study also found that visual and audio elements enhanced comprehension, memory retention, and speaking confidence. Students reported increased interest in using video-based resources and preferred interactive strategies such as quizzes and group projects. The findings suggest that asynchronous YouTube-based instruction provides a flexible and engaging platform for vocabulary development and recommend its integration into English language learning curricula in similar educational contexts.