is 1.85. Because F hitung 1.53 1.85 then we can conclude that the data of both pretest is homogeny.
While the homogeneity of post-test of both groups was computed as follow:
F = Ve
Vc
= 50.75862069
56.36781609
= 0.900489396
The value of F table with dk numerator V1 = n1 - 1 = 30 - 1 = 29, dk denominator v2 = n2-1 = 30 -
1 = 29 and α = 5, squared to V1 =30 and V2 = 30 is 1.85. Because F hitung 0.90 1.85 then we can conclude that the data of both
pretest is homogeny.The computation of homogenity can be seen in Appendices.
4.3 Difference between the Two Means
After analyzing the normality and homogeneity of the data, the computation was made. The first way to identify the significant difference between the control and
experimental groups were by comparing the different means of both groups. The data being compared were the difference between the two means of the pre-test
and post-test, because the data showed the result of the treatment. The difference between the two means was computed using the following
formula as stated by Arikunto 2002:264:
Ne Xe
Xe
Nc
Xc Xc
Where:
Xe = the mean of the experimental group
Xc = the mean of the control group
Xe =
the total of the students‟ scores in the experimental group
Xc = the total of the studen
ts‟ scores in the control group Ne
= the number of the students in the experimental group Nc
= the number of the students in the control group
The mean of the control group on the pre-test: ��
= �� ��
= 1952
30 = 60.07
The mean of the control group on the post-test: ��
= �� ��
= 2300
30 = 76.67
Whereas, the mean of the experimental group on the pre-test: ��
= �� ��
= 1964
30 = 65.47
The mean of the experimental group on the post-test: ��
= �� ��
= 2520
30 = 84.00
From the calculation, it can be seen that in the control group, the mean of the pre-test was 65.07 and the post-test 76.67. From those scores, the different
mean between the pre-test and the post-test on the control group was 11.60. While, on the experimental group, the mean of pre-test was 65.47 and post-test
was 84.00. The different mean between those tests was 18.53. It meant that the different mean on the experimental group was higher than that of the control
group. It could be concluded that there was good improvement of the
experimental groups achievement after they received the treatment using BBC Nature videos. However, it could not be concluded that the difference between the
two means of pre-test and post-test was significant. Therefore, to determine whether the difference between the two means was statistically significant, the t-
test formula was applied.
4.4 Analyzing the T-test
