However, in controlled class 4 13.3 students in range 21-30 who had highest gained score. Then the mean score of experimental class was 14,27 while the
controlled class was 12.67, the difference between the mean score was 1.6. The highest gained score in experimental class was 32 and the lowest gained score was
-8. While in controlled class the highest gained score was 24 and the lowest was 0. More details of students gained score and calculation were attached in the
appendix.
B. Preliminary Analysis
Before doing data testing t-test preliminary analysis should be done. The preliminary analysis consisted normality test and homogeneity test. This
preliminary analysis was done in order to see whether the data was normally distributed or not and homogenous or not. In order to find the normality and the
homogeneity of the data, the writer used IBM SPSS Statistics 22.
1. Normality test
a. Pre-test Normality Test
Table 4.4
Tests of Normality
Class Kolmogorov-Smirnov
a
Shapiro-Wilk Statistic
df Sig.
Statistic df
Sig. Pretest
Eksperiment .153
30 .072
.958 30
.280 Control
.101 30
.200 .962
30 .343
. This is a lower bound of the true significance. a. Lilliefors Significance Correction
The normality test used Kolmogorov-Smirnov. Based on critical points table Kolmogrov-Smirnov see appendix
, if N was 30 and α was 0.05, then the t
table
was 0.242. As could be seen on table 4.4 that t
value
of experimental class was 0.153 while the t
value
of controlled class was 0.101. If the t
value
was smaller than t
table
t
value
t
table
, the data was normally distributed. If it was not, the data was not normally distributed. From the table 4.4 above t
value
experimental class was smaller than t
table
0.1530.242 and t
value
of controlled class also smaller than t
table
0.1010.242. From those data it could be concluded that the data was normally distributed.
b. Post-test Normality Test
Table 4.5
Tests of Normality
Class Kolmogorov-Smirnov
a
Shapiro-Wilk Statistic
Df Sig.
Statistic df
Sig. Posttest
Experiment .113
30 .200
.952 30
.194 Control
.143 30
.123 .973
30 .621
. This is a lower bound of the true significance. a. Lilliefors Significance Correction
The normality test in table above was Kolmogorov-Smirnov. Based on critical points table Kolmogrov-Smirnov see appendix
, if N was 30 and α was 0.05, then the t
table
was 0.242. According to the table 4.5, it could be seen that t
value
of experimental class was 0.113, while the controlled class was 0.143. If the t
value
was smaller than t
table
t
value
t
table
, the data were normally distributed. Then if it was not, the data were not normally distributed. It could be seen in the table above that
t
value
in experimental class and controlled class were smaller than t
table
. It was 0.1130.242 in experimental class and 0.1430.242 in controlled class. It can
be concluded that the data was normally distributed.
2. Homogeneity Test
a. Pre-test Homogeneity test
Table 4.6
Test of Homogeneity of Variances
Pretest Levene Statistic
df1 df2
Sig. .633
1 58
.464
The writer used Levene Statistics in order to find the homogeneity of the pre- test with the significance level 0.05. Then from the table above, it could be seen
