Techniques of Collecting Data
21 40 65
-25 625
22 40 65
-25 625
23 60 55
5
25
24 45 75
-30
900
25 55 65
-10
100
26 55 65
-10
100
27 55 55
N= 36 ∑x = 1350
∑x = 1680 ∑ D = -330
∑ D
2
= 9900
Notes:
N = Number of cases
x = The score of pre-test
y = The score of post-test
D = Difference
∑x
= The total score of x
∑y
= The total score of y
∑D = The total of difference ∑D
2
= The total of quadrate difference
Based on the data in the table , writer calculated the result of ∑ D = -330
and ∑ D
2
= 9900. Then, the writer tried to find out the standard deviation with the formula:
SD
D
= ∑ D
2
∑ D
2
N N
= 9900 -330
2
27 27 = 366.67
-12.22
2
= 276.38 149.38
= 217.28 = 14.73
Based on that computation, the standard deviation is 14.73. the standard deviation is used to find out the standard error from mean of difference.
Next the writer tried to know mean of difference. It is used by the formula:
MD = ∑ D
N = -330
27 = -12.22
From that calculation the MD is -12.22, this calculation is used for finding out t-test.
Meanwhile to get SE
MD
Standard Error of the Mean of Difference, the writer used the formula as follows:
SE
MD
= SD
D
N-1 = 14.73
27-1 = 13. 11
26
= 13. 11
5.09 = 2. 89
From that calculation it could be seen that the standard error of the mean difference is 2.89. This SE
MD
is used to find out the T-Test.
Furthermore, to get t
o
t observation of the test, the writer used formula: to = MD
SE
MD
= -12.22 2.89
= - 4.22 Based on that computation, it indicates that the T-test is -4.22, it means
there was a difference of degree as much as – 4.22. Regardless the minus, it does not indicate negative score. The result of analyzing the data above it shows that
the coofecient is 4.22. Then, to find critic “t” result in t-table, then the writer must calculate
degree of freedom with formula as follows: df = N – 1
= 27 - 1 = 26
df = 26 See table of “t” value at degree of significance of 5 and 1 in appendix 4
Degree of Significance Degree of freedom
5 2.06 1 2.78
Statitiscal Hypothesis:
a If t
o
t
t
: There is a significant deference and the alternative hypothesis Ha is accepted and null hypothesis Ho is rejected.
b If t
o
t
t
: There is no significant deference and the alternative hypothesis Ha is rejected and null hypothesis Ho is accepted.
The value of t
o
has been found with the amount 4.22. so, with formula The result is 2.06 4.22 2.78, it means that t- observation is higher than t-
table.
According to the data, the score of t
o
is higher than t
t
which means that the alternative hypothesis is accepted and null hypothesis is rejected. There is a
significance increases that the simple present tense taught through contextual teaching and learning approach.