The research that has been conducted entitled “The effect of Hello Talk application on students’ vocabulary mastery at seventh grade Al-Abrar Sihuik-huik Tapanuli Selatan”. The primary objective of this study is to assess whether the Hello Talk application has a significant impact on the vocabulary skills of seventh-grade students at MTs Al-Abrar Sihuik-huik during the 20232024 academic year. This research employs a quantitative quasi-experimental approach and was carried out with a total of 40 students, divided into two groups: 20 in the experimental group and 20 in the control group. Data collection involved the administration of multiple-choice tests as evaluation tools, including a pre-test conducted before the intervention and a post-test conducted afterward. The collected data were statistically analyzed using a t-test in SPSS 23, with a significance level set at 5% (0.05).
Analysis revealed that the experimental group's mean post-test score (83.5) was higher than the control group's (72) after all. The t-test result (3.162) exceeded the threshold t-value of 2.024 with 38 degrees of freedom at a 5% significance level (0.05). As a result, the result of the t0 > t table resulted in the alternative hypothesis (Ha) being accepted and the null hypothesis (H0) being rejected. Additionally, the calculated effect size was 1.30, which is within the range for strong effects. As a result, it can be said that the Hello Talk app significantly affects the language competency of seventh-grade pupils at MTs AlAbrar Sihuik-huik
