Table 4.6 Mean Scores Comparison Pre-Test
Post-Test Progress
Experimental Group 68
84.3 16.3
Control Group 66.7
78.2 11.5
The table above demonstrated that there were improvements in both groups. However, the progress of the experimental group which taught by
subtitled English songs were higher than the control group which taught by Grammar Translation Method. To prove the significant improvement of both
groups, the results need to be tested by using t-test.
4.3.3 t-Test Statistical Analysis of the Pre-Test and Post-Test of the Experimental Group
To find the t-test of pre-test and posttest of the experimental group, first I calculated the gain or difference result of the post-test and pre-test. Here, the gain
or difference is symbolized by d. When the value of d is obtained, then the square of d can be calculated d
2
. To see the complete calculation, look at this table below:
Table 4.7 Pre-Test and Post-Test of the Experimental Group NO.
CODE PRE-TEST
X1 POST-TEST
X2 d
X2-X1 d
2
1 E-01
70.0
86.7
16.7 278.89
2 E-02
66.7
86.7
20 400
3 E-03
66.7
83.3
16.6 275.56
4 E-04
63.3
70.0
6.7 44.89
5 E-05
70.0
83.3
13.3 176.89
6 E-06
70.0
76.7
6.7 44.89
7 E-07
73.3
76.7
3.4 11.56
8 E-08
73.3
96.7
23.4 547.56
9 E-09
66.7
83.3
16.6 275.56
10 E-10
63.3
86.7
23.4 547.56
11 E-11
66.7
80.0
13.3 176.89
12 E-12
70.0
83.3
13.3 176.89
13 E-13
66.7
76.7
10 100
14 E-14
63.3
90.0
26.7 712.89
15 E-15
76.7
86.7
10 100
16 E-16
56.7
86.7
30 900
17 E-17
56.7
76.7
20 400
18 E-18
70.0
83.3
13.3 176.89
19 E-19
76.7
96.7
20 400
20 E-20
76.7
96.7
20 400
21 E-21
66.7
83.3
16.6 275.56
22 E-22
56.7
86.7
30 900
23 E-23
56.7
66.7
10 100
24 E-24
76.7
83.3
6.6 43.56
25 E-25
70.0
80.0
10 100
26 E-26
73.3
83.3
10 100
27 E-27
63.3
86.7
23.4 547.56
28 E-28
73.3
90.0
16.7 278.89
29 E-29
66.7
86.7
20 400
30 E-30
70.0
90.0
20 400
31 E-31
66.7
86.7
20 400
32 E-32
73.3
86.7
13.4 179.56
∑ 32
2177 2697
520.1 9872.05
�
̅
68 84.3
Next, after gaining the value of d, the mean difference of the pre-test and post-test could be made by using formula stated by Arikunto as follows:
� = ∑�
� Arikunto 2006:307
As a result, it was obtained that � =
� . 2
= 16.253
Then, the next step was to calculate the value of ∑X
2 d
by using formula as below:
∑X
2 d
= ∑d
2
− ∑d
2
N Arikunto 2006: 308
Hence ∑X
2 d
= ∑d
2
−
∑d N
= 8 . −
� . 2
= 8 . −
2 . ,
2
= 8 . – 8453.25
= 1418.749
After processing the pre-test and post-test, then the t
test
could be calculated as follows:
� =
�� √
∑� � � �−
in which, t
= t
test
Md = mean difference of pre-test and post-test
X
d
= deviation of each subject d-Md ∑X
2 d
= sum of deviation square
N = number of subject
Arikunto 2006: 307
� =
�� √
∑� � � �−
= 1 .
√ 1 18. − 1
= 1 .
√1 18.
= 1 .
√1. =
1 . 1.1
= 13.60
Finally I obtained the value of t
test
that was 13.60
Before stating whether the result is significant or not, I needed to consult it first with the value of t
table
. Here, first I defined the degree of freedom d.f on which:
�. � = � − 1 Arikunto 2006:308
The degree of freedom then obtained as follows: �. � =
− 1 �. � = 31
Thus, the writer needed to find out the definite value of t in the 5 alpha level of significance and 30 degrees of freedom by using interpolation as the
following: t-table for 30 df = 2.042
60 df = 2.000
t-table for 60 =
2. 2−� 2. 2−2.
=
− −
2. 2−� . 2
= −
−
2.042 – t x -30 = -1 x 0.042
-61.26 + 30 t = -0.042 30 t = -0.042 + 61.26
30 t = 61.218 t = 2.041
Based on the computation, the critical value on the t-table for 31 degrees of freedom and 5 alpha level of significance is 2.041. Because t-value is higher
than t-table 13.60 2.041, it means that there is significant differences in the experimental group after they received treatments using subtitled English songs.
4.3.4 t-Test Statistical Analysis of the Pre-Test of the Experimental and Control Group
