means score there was difference, the formula with the significance degree 5 and 1. The formula as follows
2
;
to = MD SE
MD
MD : Mean of difference: the average score from the differences gained scores
between I variable and II variable, which are calculated with the formula;
MD = ∑ D
N ∑ D : Total score between variable I variable X and variable
II variable Y. And D is gained with formula; D = X – Y
N : Number of Class
SE
MD
: The standard error from mean of differences that is gained with the formula;
SE
MD
= SD
D
N-1 df
: Degree of freedom with formula: N – 1
SD
D
: The standard deviation from the differences between score of X variable and Y variable, which is gained with the formula:
SD
D
= ∑ D
2
∑ D
2
N N
51
Anas Sudjono, Pengantar Statistik Pendidikan , Jakarta: PT. Raja Grafindo Pustaka, 1997, Cet. Ke-8, p. 289
B. RESEARCH FINDINGS
1. Description of Data
After conducting the research, the writer obtained two kinds of data; the scores of the pre-test and the scores of post-test.
a. The Pre-Test Scores
Table 4.2 The Result of the Students’ Pre-test
No. Score Pre-Test No.
Score Pre-Test
1 60 15
35 2 65
16 40
3 65 17
60 4 65
18 50
5 45 19
60 6 60
20 55
7 50 21
40 8 35
22 40
9 30 23
60 10 35
24 45 11 35
25 55 12 40
26 55 13 45
27 55 14 60
To get the students’ mean score, the writer used the formula as follow: • Mx =
∑ x = 1350 = 50 Mean score N
27 27 Based on that calculation, the students’ mean score is 50, it means their English
score should be improved.
b. The Post-Test Scores
Table 4.3
The Result of the Students’ Post-test No. Score Post-Test
No. Score Post-Test
1 85 15
70 2 50
16 75
3 70 17
65 4 75
18 65
5 60 19
50 6 50
20 75
7 60 21
65 8 55
22 65
9 70 23
55 10 35
24 75 11 65
25 65 12 45
26 65 13 55
27 55 14 60
To get the students’ mean score, the writer used the formula as follow: • Mx =
∑ x = 1680 = 62.22Mean score N
27 Based on that calculation, the students’ mean score of post-test is 62.22, it means
that there are some students’ improvement score from pre-test to post-test. It is 12.22 62.22 – 50
