4.2.1. Homogeneity of the Pre-test of Experimental and Control Group
The computation of homogeneity was needed to find out the similarity of both experimental and control group in their English vocabulary achievement. If the
results of homogeneity of experimental and control group are not homogeny, the treatment cannot be conducted because homogeneity influences the test result and
they do not have the same ability in vocabulary achievement. The homogeneity of pre-test of experimental and control group was
presented as follows: F =
F = F = 1.33
The value of F table with dk numerator V
1
= n
1
– 1 = 31 – 1 = 30, dk denominator V
2
= n
2
– 1 = 31 – 1 = 30 and α = 5, squared to V
1
= 31 and V
2
= 31 is 1.83.
The result showed that experimental and control group were homogenous since the f-value 1.33 was lower than f table 1.83. By knowing the result of
homogeneity test, the writer concluded that the research could be continued. The computation of pre-test of homogeneity can be seen in Appendix 14.
4.2.2. Normality of the Pre-test of the Experimental Group
The normality was counted to know whether the group is normally distributed. If the scores are not normal, the treatment cannot be conducted because they do not
have same average in vocabulary achievement. Based on the data of normality, the X
2
value of pre-test of experimental group was 2.86. Besides that, the computation of X
2
table was X
2
αdk = X
2
5 3 = 7.82. It showed that the X
2
value X
2
table then pre-test score for experimental group was said to be normally distributed. The complete
computation of normality can be seen in Appendix 15.
4.2.3. Normality of the Pre-test of the Control Group
Based on the data computation, the normality of pre-test of control group showed that the X
2
value was 7.65. Then, the writer computed the X
2
table. The computation of X
2
table was X
2
αdk with α = 0.05 and dk = 3. Since the data of normality X
2
was lower than the X
2
table 7.65 7.82, the data were considered to be normally distributed. The computation of normality can be seen
in Appendix 16.
4.3. Treatment Activities
Kategori