: the mean of the pre-test of the experimental group : the mean of the pre-test of the control group
: the number of the experimental group : the number of the control group
: standard deviation : standard deviation of the experimental group
: standard deviation of the control group
2 If the data do not have the same variances, then the formula which is
used is as follows:
The testing criteria are based on Sudjana 2005:243: Ho is rejected if
, and Ho is accepted if it happens the
otherwise. Where ; t
1
= t
1- α.n1-1
; t
2
= t
1- α.n2-1.
3.5.2 Analysis of the Final Stage
a Test for normality
The statistical formula used in the normality test is:
Sudjana, 2005:273 Where:
O
i
= the observed frequencies E
i
= the expected frequencies k = the number of class intervals
X
2
= the X
2
value from calculation ∑ = the sum of
With degrees of freedom dk = k - 3 and α = 5. If X
2 data
≤ X
2 1-
αk-3
, it means that the data are normally distributed.
b Testing the equality of two variances
To test the equality of two variances, the formula is as follows:
Sudjana, 2005:251 Paired hypotheses which were tested are:
Ho : σ
1 2
= σ
2 2
Hi : σ
1 2
σ
2 2
The testing criteria are: Ho is rejected if F ≥ Fα v1, v2 with α = 5. Where v
1
= n
1
-1 dk numerator dan v
2
= n
2
-1 dk denominator.
c T-test for Post-test
T-test formula was applied to measure whether there was significant difference between experimental and control groups on post-test scores.
The hypotheses which were tested are: Ho
: μ
1
= μ
2
Hi : μ
1
μ
2
To test the truth of the hypotheses, the researcher used one tailed t-test. It is used in two ways:
1 If the data have the same variances, then the statistic which is used is t-
statistic, which could be written as follows:
Criteria: Ho is accepted if t
value
t
table
. Meanwhile, Ho is rejected if t
value
has another value, with α = 5 and dk = n
1
+ n
2
– 2. Sudjana, 2005:243 Where:
t : t-test
: the mean of the post-test of the experimental group : the mean of the post-test of the control group
: the number of the experimental group : the number of the control group
: standard deviation : standard deviation of the experimental group
: standard deviation of the control group
2 If the data do not have the same variances, then the formula which is
used is as follows:
The testing criteria are based on Sudjana 2005:243: Ho is rejected if
, and accept Ho if it happens the
otherwise. Where ; t
1
= t
1- α.n1-1
; t
2
= t
1- α.n2-1
.
41
CHAPTER IV DATA ANALYSIS AND DISCUSSION
This chapter presents the data analysis and the discussion of research findings. It consists of pre-test analysis, treatment processes, post-test analysis, discussion of
the research findings, and some obstacles in doing a research.
4.1 Pre-test Analysis
