Abstract :
Vocabulary acquisition plays a fundamental role in language development.
This study focuses on measuring the improvement of students' vocabulary skills
before and after using the Duolingo application, as well as comparing the
effectiveness of vocabulary learning with and without the app. Furthermore, the
study also aims to identify the most problematic English word class for students in
the context of Mobile Assisted Language Learning. This research study employed
a quantitative design. The sample of the study is 30 seventh-grade students from
class VII-A. The research instruments included vocabulary tests and a
questionnaire. The data collection process involved administering the pre-test,
followed by the treatment using the Duolingo application, and finally conducting
the post-test. The collected data was analyzed using SPSS 25.0 for Windows,
including N-Gain, normality, and homogeneity tests. The findings revealed that the
use of Duolingo had a significant positive effect on enhancing students' vocabulary
abilities. After utilizing the Duolingo application, the post-test results demonstrated
a significant improvement in the students' vocabulary skills. The paired sample t?test further confirmed the effectiveness of Duolingo in enhancing vocabulary
proficiency. Moreover, the study also identified adverbs as the most problematic
English word class for the students.
Keywords: Effect, Duolingo application, vocabulary skills