The Effect of Using Duolingo Application as a Media Toward Students' Vocabulary Mastery at The Second Grade of SMPN 1 Lembah Gumanti
ABSTRACT Mona Hastuti, 2314.090. The Effect of Using Duolingo Application Toward Students Vocabulary Mastery at the Second Grade of SMP N 1 Lembah Gumanti . A Thesis, State Islamic Institute of Bukittinggi, 2019. This research was done based on researchers’ observation in SMPN 1 Lembah Gumanti. The researcher found several problems that were felt by students at the second grade of SMP N 1 Lembah Gumanti in learning English vocabulary were many students lack of vocabulary and they were uninterested and unmotivated in learning English vocabulary because of the teacher still applied traditional tecnique in teaching vocabulary and they were easy to forget the new vocabulary they had learned. This research was aimed at discovering the effect of using Duolingo application toward students’ vocabulary mastery at the second grade of SMPN 1 Lembah Gumanti. This research was an quantitative method. The population of this research was the second grade of SMPN 1 Lembah Gumanti . in this research, the researcher used random sampling technique in determining the sample. There were two classes as the sample of this research. Class VIII.A was as the experimental class and class VIII.B as control class and each of class consist of 24 students class VIII.A and 21 students class VIII.B and both of classes were given pretest and different treatment. In the experimental class the students were taught by using Duolingo application. While, in control class the students were taught by using traditional technique and both of classes were given post test at the end of meeting. In order to analyze the data, the researcher used the normality test by using Liliefors test and tested the homogeneity of the data by using F test. The researcher also used the t-test formula to test the hypothesis and consulted its result with the ttable with α = 0.05. The result of this research shows that the students who used Duolingo application score is 4,62 (tcount is higher than ttable), while at the students who did not use Duolingo application score 3,03 (tcount is higher than ttable). The t test calculation showed that there was a significant difference who use Duolingo application and who did not use Duolingo application. It means that Ho was rejected and Ha was accepted. So, Duolingo application was effective to improve English vocabulary at the second grade of SMPN 1 Lembah Gumanti.