b. The Data of the Post-test Scores of the Control Class
Based on the result of statistical calculating by using SPSS 13.00 for windows computer program, the mean score was 66.09 with the standard
deviation 7.15. The maximum score for the post-test of the experimental group was 85.00 and the minimum score was 50.00. The statistical data can be seen in
Table 16 and the data analysis is in Appendix C.
Table 16: Descriptive Analysis of the Post-test of the Control Class N
Mean Std.Deviation
Minimum Maximum
Post-test
32 66.09
7.15 50.00
85.00
Meanwhile, the frequency distribution of the post-test score on the experimental group is presented in Table 17.
Table 17: Frequency Distribution of the Post-test score on Students’ Writing Ability of the Control Class
No Interval
f Percent
Cumulative Percent
Categorization
1. 87.5 – 99.9
Excellent 2.
75.0 – 87.4 4
12.5 12.5
Very Good 3.
62.5 – 74.9 19
59.4 71.9
Good 4.
50.0 – 62.4 9
28.1 100.0
Fair 5.
36.5 – 49.9 100.0
Poor 6.
25.0 – 37.4 100.0
Very Poor
Table 17 shows that there were no students classified into excellent, poor and very poor categories. There were 9 students 28.1 in fair category, 19
students 59.4 in good category, and 4 students in very good category 12.5 on the post-test or after they were given treatment using inquiry based-learning
strategy.
c. Comparison Data between the Pre-Test and Post-Test of the Control
Class
To know the difference of pre-test and post-test of the control class in writing ability, comparison between both scores is showed in Table 18.
Table 18: Statistical Data of the Pre-Test and Post-Test Scores of the Control Class
Data Pre-Test
Post-Test Number of cases
32 32
Mean
57.10 66.09
SD
7.45 7.15
Based on Table 18, the mean score of the pre-test of control class was 58.10 which was classified into fair category. Meanwhile, the mean of the post-
test was 66.09 which was classified into good category. The data shows that the mean score of the post-test was higher than that of pre-test score. Thus, the mean
score of post-test was higher than the mean of pre-test score. Beside the improvement of the mean value, there was an improvement of the scoring
category from fair to good category. It means that the writing ability of the control class improved after being taught without using inquiry based-learning strategy.
Moreover, the standard deviation SD for the pre-test was 7.45, while the post-test was 7.15. Thus, the SD of the post-test is lower than the SD of the pre-
test. If the SD of the post-test was lower than the SD of the pre-test, it can be interpreted that the students’ writing abilities of the control class on the pre-test
and post-test scores were homogenous. In addition, on the pre-test there were 37.5 of students in good category
which achieved scores above the ideal mean and 62.5 of students in poor
category which achieved score below the ideal mean 62.5. The pre-test score on the students’ writing ability of the control group did not achieve the ideal mean
because the score of most students is below the ideal mean. Besides, the percentage of students achieving scores below the ideal mean were higher than
those achieving scores above the ideal mean i.e. 62.5 36.5. It meant that the result of the pre-test score on the students’ writing ability of the control group
is classified into the poor category. Meanwhile, on post-test, there were 71.9 of students in good category
who achieved scores above the ideal mean and 28.1 of students in poor category who achieved scores below the ideal mean. The post-test score on the students’
writing ability of the control group achieved the ideal mean because the score of most students was above the ideal mean. Further, the number of students
achieving scores above the ideal mean were higher than those achieving scores below the ideal mean i.e. 71.9 28.1. From the explanation above, it could
be summarized that there was improvement 34.4 from the pre-test to post-test in control class.
B. Inferential Analysis
The inferential analysis describes pre-testing analysis and hypothesis testing as presented below.
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