Abstrak
Vocabulary mastery plays a vital role in English learning, helping students to understand information, communicate effectively and develop their language skills. However, many seventh-grade students at MTsN 5 Lima Puluh Kota still struggle to master vocabulary. These difficulties are generally related to their limited vocabulary and lack of engaging learning materials. This study therefore aims to determine the effect of using the Anki app on vocabulary mastery, and to examine differences in learning outcomes between students taught using the app and those taught through conventional methods. The study employed a quantitative approach with a quasi-experimental design, specifically a non-equivalent control group design. The study participants consisted of two seventh-grade classes at MTsN 5 Lima Puluh Kota, selected using purposive sampling. Data were collected using a 20-item, multiple-choice vocabulary test, which was administered as both a pre- and post-test. Descriptive and inferential statistics were employed in the data analysis using SPSS software. The results showed that the experimental class demonstrated significantly greater improvement than the control class. The statistical analysis yielded a p-value of less than 0.05, indicating that the Anki app has a positive and significant impact on students' vocabulary acquisition. Therefore, it can be concluded that the Anki app is an effective learning tool for improving English vocabulary mastery.