IMPROVING VOCABULARY MASTERY OF THE SEVENTH GRADE STUDENTS AT SMP NEGERI 30 SIGI THROUGH TREE DIAGRAM TECHNIQUE

The objective of this research is to improve the students’ vocabulary
mastery through tree diagram technique. This research employed quasi�experimental research design, consisting of experimental and control group. The
population is the seventh grade students and the sample is VIIA and VIIB
consisting of 21 students for each. The researcher applied purposive sampling
technique in selecting the sample. In collecting the data, the researcher used test
(pre-test and post-test) as the research instrument. To analyze the data, the
researcher used statistical analysis by applying t-test formula. The result of data
analysis shows that the hypothesis of the research is accepted by regarding that
the tcounted (4.134) was higher than the ttable (2.021) which the degree of freedom
(df) of the table is Nx + Ny – 2 = 21 + 21 – 2 = 40 with the level of significance,
0.05. In conclusion, tree diagram technique can improve the vocabulary mastery
of the seventh grade students.