44
4.1.1 The Descriptive Statistic of Pre-test Result
Before the experiment began, both groups had to take part in the pre-test. The tests were assessed by using the rubric adapted from Wagner’s book, which
focused on writing for senior high school students. Table 4.2. and figure 4.2. show the descriptive statistic of pre-test for the experimental group.
Table 4.2. The Distribution Table of Pre-test Result of Experimental Group
Pretest
Frequency Valid
44.00
1
47.00
3
50.00
2
53.00
3
56.00
9
59.00
5
63.00
6
66.00
10
69.00
4
72.00
5
75.00
3
78.00
1
91.00
1
Total
53
The information in the table 4.2. presents the distribution of the pre test results of the experimental group. The mode was 66. The mean score or the post-
test was 62.47, and the standard deviation was 9.14. The difference from highest to lowest was 47 points, almost five times standard deviation, which ranges from
44 to 91. This reflects that the score distribution of the pre test of the experimental group was quite clumped. For the complete score of the experimental group’s pre-
test, please refer to APPENDIX 9.
Statistics
Pretest N
Valid
53
Missing Mean
62.4717
Std. Deviation
9.14962
Figure 4.1. The comparison of pre-test and post-test
45
Figure 4.2. The Distribution of Pre-test Result of Experimental Group
The graphic shows normal distribution of the pre-test results, as the distribution is in bell shape. As seen above, the highest frequency belongs to 60
and 70. As a comparison, the researcher also collected the pre-test results of the
control group. This group got no treatment. The distribution of the pre-test results of the control group could be seen in table 4.3.
The information in table 4.3. presents the distribution of the post test result of control group. There was bimodal: 56 and 66. The mean score for the post-test
was 63.05, and the standard deviation was 9.63. The difference from highest to lowest was 53 points, almost five times standard deviation, which ranges from 44
to 91. This reflects that the score distribution of the pre tests of the control group was quite clumped. For the complete score of control group’s pre-tests, please
refer to APPENDIX 10.
46
Table 4.3. The Distribution Table of the Pre-test Result of Control Group
Pretest
Frequency Valid
44.00
1
47.00
3
50.00
1
53.00
5
56.00
8
59.00
4
63.00
5
66.00
8
69.00
6
72.00
3
75.00
5
78.00
2
91.00
1
Total
52
Figure 4.3. The Distribution of Pre-test Result of Control Group
The graphic shows negatively skewed distribution of the pre-test result, as the distribution was slightly concentrated on the right side in the figure. As seen
above, the highest frequency belonged to 70.
Sta tistics
Pretest N
Valid
52
Missing Mean
63.0577
Std . Deviat io n
9.63941
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