From the results of the treatments until the post-test, the average scores of the experimental group were higher than those of the control group. It shows that
teaching using study tour method is needed to increase the students‘ skill in writing descriptive text.
4.4 Difference between the Two Means
After getting all the scores, the computation was made. The means which were gathered in the research would reflect the different effectiveness of the treatments
given to both groups. The writer applied the t-test formula to count the difference. The following formula was used to get the means:
N Xe
Me
N
Xc Mc
Where; M
e
: the mean score of the experimental group Mc
: the mean score of the control group ∑Xe
: the sum of all scores of the experimental group ∑Xc
: the sum of all scores of the control group N
: the number of the subject sample According to the formula, the mean of the control group in the pre-test and
the post-test was:
c
= −
= 1824
− 1660 26
= 164
26 = 6.31
In addition, the writer also found out the mean of the experimental group in the pre-test and the post-test:
e
= −
= 2000
− 1656 26
= 344
26 = 13.23
Besides the writer used the formula above, she used other calculation to count the means of the experimental and the control groups. This analysis found
the mean of each test of both groups. The mean of the experimental group on the pre-test is:
M
1
=
�
=
1656 26
= 63.69 The mean of the experimental group on the post-test is:
M
1
=
�
=
2000 26
= 76.92
The mean of the control group on the pre-test is: M
2
=
�
=
1660 26
= 63.85 The mean of the control group on the post-test is:
M
2
=
�
=
1824 26
= 70.15 From the calculation, it can be seen that on the experimental group, the
mean of the pre-test was 63.69 and the post-test was 76.92. From those scores, the different mean between the pre-test and post-test was 13.23. While, on the control
group, the average score of the pre-test was 63.85 and the post-test was 70.15. The different average score between those tests was 6.3.
Based on the calculation, it could be concluded that the different average score on the experimental group was higher than on the control group. It means
that there is good improvement of the experimental group which was taught by using study tour method to increase the skill in writing descriptive text.
However, it could not be concluded that the difference between the two means of the pre-test and the post-test was significant. Therefore, to determine
whether the difference between the two means was statistically significant, the t- test formula was applied.
4.5 Analyzing the t-test
