Abstract:
This study is aimed to investigate the effect of numbered head together (NHT)
strategy on students vocabulary mastery assisted by crossword puzzle game and to
find out the students difficulties in vocabulary by using numbered head together
(NHT) strategy. This is an experimented research design which used the descriptive qualitative method in analyzing the data. The data of this research was the
VIIIth grade students of SMP Muhammadiyah 58 Sukaramai, Medan. In the
2018/2019 academic year by using total sampling methods, 50 students were chosen as the sample. The sample was divided into two groups; 25 students as experimental ground and 25 students as control group. The experimental group was
given treatment by group numbered head together (NHT) and control group using
direct method. The instrument of the research is written test, which used pre-test
and post-test. The result of this research showed that tobserved (2.8 > 2.01) with a =
0.05 and df = 48 . It means Ha is accepted. Therefore there were significant effects
of using numbered head together strategy on students’ vocabulary mastery
