Based on the table above, the mean of students’ score in the pretest was
56.46 with the lowest score, 36, and the highest score, 77. Meanwhile the mean score of posttest was 65.54 with the lowest score, 43, and the highest score, 82.
Based on the data in the tables above, it showed that the students’
achievement in writing narrative text by using English comic strips in experimental class was higher than the students in controlled class without
English comic strips. It was also described by the figure of chart below:
Figure 4.1 Mean Score of Pretest, Posttest, and Gained Score of Experimental and
Controlled Class
B. Data Analysis
The data of students’ score was analyzed by using t-test to prove whether
there was any significant different between student s’ ability in writing narrative
text in the experimental class as the X variable and controlled class as the Y variable. But, before using the formula of t-test, t
he students’ score in the experimental and controlled class were tabulated to calculate the gained score of
each class. It could be seen as follows:
10 20
30 40
50 60
70 80
90 100
Experimental Class Controlled Class
Pretest Posttest
Gained Score
Table 4.3 Statistical Calculation of Gained Score Both the Experimental and
Controlled Class No
X Y
X-MX Y-MY
X-MX2 Y-MY2
1 28
25 5
16 25
256 2
28 11
5 2
25 4
3 23
-21 -30
900 4
19 20
-4 11
16 121
5 17
8 -6
-1 36
1 6
26 -4
3 -13
9 169
7 26
7 3
-2 9
4 8
28 24
5 15
25 225
9 27
4 -9
16 81
10 14
32 -9
23 81
529 11
19 9
-4 16
12 27
-8 4
-17 16
289 13
11 20
-12 11
144 121
14 23
-1 -10
100 15
15 39
-8 30
64 900
16 30
2 7
-7 49
49 17
35 29
12 20
144 400
18 17
18 -6
9 36
81 19
13 7
-10 -2
100 4
20 43
-13 20
-22 400
484 21
14 9
-9 81
22 47
-13 24
-22 576
484 23
37 14
-9 196
81 24
15 9
-8 64
25 13
20 -10
11 100
121 26
33 5
10 -4
100 16
27 11
9 -12
144 28
13 11
-10 2
100 4
Total 652
254 8
2 2572
5424 Mean 23.28571 9.071429
91.85714 193.7143
According the data in the table above, the result of students’ pretest and posttest further in each class was calculated by using t-test in some steps as
follows: 1.
Determining mean of variable X, with formula as follows:
