further. The data, then, were analyzed the difference between two means of the
experimental and control groups. Afterwards, the t‐test formula was applied in order to
determine the significance between the two means, resulting with the conclusion of the
data finding by examining the hypotheses.
4.3.1 Normality
It is necessary to make sure that the data are normal before computed by the t‐test
computation. Thus, the normality of the data were analyzed after the data gathered.
The data of this study found that the x
2 value
of pre‐test and post‐test of the experimental
group were 4.269 and 6.093, while the pre‐test and post‐test of the control group were
5.362 and 6.221.
The next step was consulting those data result with critical value of x
2 value
αdk with
α = 0.05 and dk = 3, resulting in 7.815 points. Since the value of x
2 value
αdk of the pre
‐test and post‐test score of those two groups were lower than 7.815, the data then were
considered to be normally distributed. The computation of the normality tests can be
seen in Appendices 14, 16, 19, and 21.
4.3.2 Homogenity
Either normality or homogenity is important to be checked before analyzing the data
further. Through homogenity it is able to be checked whether the data are homogeny or
not.
The formula in computing homogenity is:
2 1
V V
F =
By using such formula, the homogenity of pre‐test of the experimental group and
control group is calculated as follows:
4632 .
1 98.67
144.37 F
= =
Then, the result was consulted with the value of F table with dk numerator v
1
= 25 – 1 =
24, dk numerator v
2
= 25 ‐1 = 24, and α = 0.05, squared to v
1
= 25 and v
2
= 25, which is
2.27. It could be considered that the data were homogeny for the F value 1.4632 F
table 2.27.
The result of the post‐test of those two groups was also computed with the same
formula in calculating the homogeneity as follows:
4103 .
1 52.00
73.33 F
= =
The result was also consulted with the value of F table with dk numerator v
1
= 25 – 1 =
24, dk numerator v
2
= 25 ‐1 = 24, and α = 0.05, squared to v
1
= 25 and v
2
= 25, which is
2.27. Since the F value 1.4103 F table 2.27, the post test of the experimental and
control groups were also said to be homogeny. The computation of homogenity can be
seen in Appendices 17 and 22.
4.3.3 Mean Difference Test
