Figure A .2. Normal Histogram of the Control Class‟ Pretest Score
Both the figure A.1 and A.2 above represented the histogram which had a shape like a bell-curve indicating that the distribution data was normal. Even
though the histog ram‟s bell-curve in the figure A.2 was fatter and shorter than
the figure one, but both curves were symmetrical. Hence, it could be said that the data of the experimental
and control class‟ pretest met the criteria of normality.
B. The Histogram of the Experimental and Control
Class’ Posttest
The following was two normal histograms which showed that the data of the experimental and control class‟ posttest score met the criteria of normal
distribution:
Figure B .1. Normal Histogram of the Experimental Class‟ Posttest Score
Figure B .2. Normal Histogram of the Control Class‟ Posttest Score
Both the figure B.1 and B.2 presented that both the histograms had a curve-bell shape look-alike and the curves were symmetrical. It meant that the
experimental and control class‟ posttest met the criteria of normality.
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APPENDIX 8 Homogeneity Test
A. Homegeneity Test
After finishing the normality test, the homogeneity test was also required as a prerequisite to do analysis test. To calculate homogeneity test, the researcher used
Levene Statistic Test from IBM Statistics SPSS 19 software. The following is the result which was obtained from this calculation:
Table A.1
Test of Homogeneity of Variances
Pretest Score Levene Statistic
df1 df2
Sig. 1.847
1 50
.180
After gaining the result of homogeneity test of the experimental and control class’ pretest, it was continued to interpret the result using the degree of significance 5
α = 0.05. The criteria of taking the decision of homogeneity test is as follow: 1. Determining the hypothesis:
H : sample data comes from population which has homogenous variance.
H
1
: sample data comes from population which does not have homogenous variance.
2. Deciding criteria to test the hypothesis: If the significance level probability
value p ≥ 0.05, H is accepted.
If the significance level probability value p 0.05, H is rejected.
From the result of the Levene Statistic Test above, it could be seen that the significance level or probability value p of the data from the experiment and
control’s pretest score was 0.180. It meant that the significacance level or
