44
Table 13: Frequency Distribution of the Pre-test Scores on Students’ Writing Ability of the experimental class
no interval
Category F
1 X ≤ 50.5 Very poor
9 56
2 50.5 ≤ X 67 Poor
6 38
3 67 ≤ X ≤ 83.5 Good
1 6
4 X ≤ 83.5 excellent
Table 3 shows that there was no student 0 classified into an excellent category. There was student 6 in a good category, 6 students 38 in a
poor category, and 9 students 56 in a very poor category. It can be concluded that the majority of the students belonged to a very poor category in the
experimental group pre-test.
b. Experimental group posttest
A posttest of experimental class aims to determine the result of student learning ability after treatment. From the posttest, data showed the highest score
achieved by students is 67 and the lowest score is 34.5. By using SPSS, it is known that the average score mean achieved by
students in the control group posttest is 45.9; mode is 36; median is 43.75; and the standard deviation is 0.0459. Frequency distribution posttest scores writing
skills through mind mapping with the experimental class are shown in Table 4 below.
45
Tabel 14: Frequency Distribution of the Post-test Scores on Students’ Writing Ability of the Experimental lass
o Interval
F 1
34-47.2 10
62.5 2
47.3-60.5 5
31.25 3
60.6-73.8 1
6.25 4
73.9-87.1 5
87.2-100 TOTAL
16 100
Based on Table 4, it is known that there are 0 students who have score 34- 47.2, 5 students who have score 47.3-60.5, student who has score 60.6-73.8, 0
students who has score 73.9-87, and 0 students who have score 87.2-00. From the statistical data, the categories of experimental class posttest are
divided into four categories, namely excellent, good, poor, and very poor.
Table 15: Frequency Distribution of the Posttest Scores on Students’ Writing Ability of the experimental class
no Interval
Category F
1 X ≤ 50.5 Very poor
11 68.75
2 50.5 ≤ X 67 Poor
4 25
3 67 ≤ X ≤ 83.5 Good
1 6.25 4 X ≤ 83.5
Excellent
46 Table 5 shows that there was no student 0 classified into an excellent
category. There was student 6.25 in a good category, 4 students 25 in a poor category, and students 68.75 in a very poor category. The conclusion
is that the majority of the students belonged to a very poor category in the posttest.
c. omparison between the Pre-Test and Post Scores of the Experimental lass
Table 6 contains the difference between the pre-test and post-test scores of the experimental class in writing ability. Based on Table 6, the mean value
of the pre-test of the experimental class was 5.3. Meanwhile, the mean of the post-test was 45.9. The data show that the mean score of the post-test was
lower than the pre-test. It can be seen from the decrease of the scoring categorization from low to very low category. It means that the writing ability of
the experimental class significantly decreased after being treated using mind mapping.
47
Table 16: Statistical Data of the Pre-Test and Post-Test Scores of the Experimental lass
Data
Pre-Test Post-Test
Number of Cases 6
6 Mean
5.3 45.9
SD 0.8
0.04 Low Category of Frequency 38
25 Very low Category of
Frequency 56
68.75
B. Inferential Analysis 1. Pre-testing Analysis
The pre-testing analysis was done before the researcher drew a hypothesis. It consists of two parts; the normality and the homogeneity tests.
Normality test was used to test whether the data show normal distribution or not, and the homogeneity test was done to test whether the sample’s variance was
homogeneous or not. The results are explained below.
