<![CDATA[This study was motivated by the low vocabulary mastery of eighth-grade students at MTsN 6 Agam due to conventional teaching methods that did not actively engage students. The study aimed to: (1) determine the effect of the List Group Label (LGL) Strategy on students’ vocabulary mastery; (2) identify the difference in vocabulary mastery between students taught with and without the LGL Strategy; and (3) compare the experimental group’s vocabulary mastery before and after the LGL treatment. This study employed a quantitative approach with a quasi-experimental nonequivalent control group design. The population consisted of 157 eighth-grade students, with Class VIII.2 as the experimental group (n = 32) and Class VIII.3 as the control group (n = 31), selected through cluster random sampling. The instrument was a 20-item vocabulary test validated through expert judgment and tested for reliability (Cronbach’s Alpha = 0.746). Data were analyzed using the Shapiro-Wilk, Levene, paired-sample t-test, and independent-sample t-test with SPSS 26 at α = 0.05. The results showed that the LGL Strategy had a significant positive effect on vocabulary mastery, with the mean score increasing from 67.72 to 76.56, a gain of 8.84 points (t(31) = -59.000; p = 0.000). A significant difference was also found between the experimental group (M = 76.56) and the control group (M = 72.74), with a difference of 3.82 points (t(61) = -4.280; p = 0.000). Thus, the LGL Strategy was effective in improving students’ vocabulary mastery compared with conventional teaching methods.]]>
