The Effect of Duolingo Application on Students’ English Vocabulary Mastery

Abstract

Quasi-Experimental research with post-test only design was used in this research as the purpose of this research was to know whether there was a significant effect of using Duolingo application on students’ English vocabulary mastery or not. The population of this research was eighth-grade students of SMPN 2 Jember. The research participants were determined based on the result of students’ homogeneity test by using ANOVA formula, in which the result showed that the population of the research was homogeneous so that the experimental class and the control class were determined by using a lottery. The number of participants was 64 in total. The experimental group consisted of 32 students and so did the control group. The participants of this research were selected by cluster random sampling; VIII-E as the experimental group and VIII-D as the control group. The experimental group got treatment by using Duolingo, while the control group used flashcard as the media.