Significant Difference between Pre test and Post test
Where, M
1
= the mean score of the pre- test M
2
= the mean score of the post- test N = the number of the students
X
1
= the number of the pre- test sores X
2
= the number of the post- test scores The computation of the mean score of the pre- test was as follows:
M
1 =
33 2245
M
1
= 68, 03 The computation of the mean score of the post- test was as follows:
M
1 =
33 2969
M
2
= 89, 96 The calculation of the means of the pre- test and the post- test were 68, 03 and
89, 96. If we compared the two mans it was clear that the mean of the post- test was higher than that the pre- test. The difference between the two means was 21, 93 M
2
- M
1
. It indicated that the treatment was effective. To make the analysis more reliable the writer analyzed it by using t- test
formula. The effectiveness of the treatment could be calculated using the following formula:
t = 1
2
−
∑
n n
d x
M
d
Where, t : t- test
M
d
: the interval of the deviation value and the mean of deviation value n : number of sample
df : the degree of freedom df : n- 1
Before applying the t- test formula, the mean of the deviation value of pre- test and post- test should be found first. The following was the process of computing
the deviation value. M
d
= n
d
∑
M
d
= 33
724
M
d
= 21, 9393 The mean of the deviation value was 21, 9393
After getting the mean of the deviation value, the computation of the t- test was as follows:
t =
1
2
−
∑
n n
d x
M
d
t =
1 33
33 8817
, 8015
9393 ,
21 −
t =
32 33
8817 ,
8015 9393
, 21
×
t=
1056 8817
, 8015
9393 ,
21
t=
5907 ,
7 9393
, 21
t= 7551
, 2
9393 ,
21
t=7, 9631 The t- value of the test was 7, 9631. For the complete data of Md, d, Xd, and
Xd
2
could be seen in appendix 10.