ABSTRACT
This research was aimed to find the effectiveness of Playing Duolingo level- up game to assist student's vocabulary mastery. This research was conducted by applying a mixed method.
Students assisting English vocabulary at seventh grade junior high school in Ciamis still low.
The value of the pre-test in experimental group with an average 61,1 while the minimum criteria of mastery learning (KKM) for seventh grade junior high school is 67. The sample was two classes with total number of 37 students taken out of the total population by applying random sampling technique. One class as the experimental group was taught by applying Duolingo game and the other class as the control group was taught by conventional strategy. The instrument for collecting the data was pre-test and post-test with 15 items of multiple choices test, 5 items of essays, and questionnaires. The data were analyzed by using the mean of the test, t-test formula and questionnaires. Data analysis resulted that t-observed value was higher than t-table value (>2.000) at level of significance 0.05 with the degree of freedom (df) 35. Since t-observed value was higher than t-table value, it means Ha was accepted and Ho was rejected. Thus, the finding of the first research question showed that teaching vocabulary mastery by using Duolingo as a medium method is effective because the score of the experimental group is highest than the control group. It is recommended for English teachers to apply the Duolingo as a medium method to assist students' vocabulary mastery.
