The Place and Time of the Research
42
2 After getting the average of students‟ post test score, the writer has to
determine the Standard Deviation score of experiment class variable X with formula used is:
SD
X
= SD
X
= Standard deviation score of Experiment class ∑
X 2
= Sum of squared of frequency multiply the student‟s score 3
Determining Standard Error Mean of experiment class variable X, with formula:
SE
X
= SE
X
= Standard Error mean of experiment class SD
X
= Standard deviation of experiment class 4
In order to know the difference of students‟ post test score between experimental and controlled class, the writer also determines students‟
score of controlled class variable Y, with the formula used is: M
Y
= M
Y
= Mean of post-test of Controlled class ∑
Y
= S um of frequency multiply students‟ score of controlled
class N
= Number of students of controlled class 5
Determining Standard Deviation Score of controlled class Variable Y, with the formula used:
SD
Y
= SD
Y
= Standard deviation score of controlled class ∑Y = Sum of squared of frequency multiply student‟s score
6 Determining standard Error of Mean of controlled class Variable Y, with
formula: SEM
Y
=
43
SEM
Y
= Standard Error mean of controlled class SD
Y
= Standard Deviation of controlled class N
Y
= Number of Students of controlled class 7
Determining standard Error of Difference of Mean of Variable X and Variable Y, with formula:
SE
MX-MY
= SE
MX 2
= Standard error mean squared of experiment class SE
MY 2
= Standard error mean squared of controlled class 8
Determining tₒ with formula: t
o
= 9
Determining t-table in significance level 5 and 1 with degree of freedom df :
df = N1 + N2 – 2
df = Degree of freedom N1= Number of students of Experiment class
N2= Number of students of controlled class