M. Data analysis
To analyze the data, the writer used parametric statistic. In the parametric statistic, there are assumptions which must be fullfilled; they are normality and homogeneity
test.
1. Fulfillment of the Assumptions
Parametric test are significant tests which assume a certain distribution of the data usually the normal distribution, assume an interval level of measurement, and
assume homogeneity of variances when two or more samples are being compared. Most common significance tests z test, t-test, and F tests are parametric.
101
It means to get a certain distribution of the data, the writer has to do some tests such as
normality test and homogeneity test.
a. Normality Test
The writer done this normality test to know whether the datas have normal distribution or not. The writer used SPSS Statistical Program for Social Science to
calculate the Kolmogorov-Smirnov test and the Shapiro-Wilks test. After the writer got conclusion that the data is normal or not, the writer may continue into the next
test. It will be homogeneity test.
The hypothesis for the normality test are formulated as follows: H
o
: the datas are normally distributed
H
a
: the datas are not normally distributed
101
G. Davin Garson,
Testing Statistical Assumption
, London: Statistical Associate Publishing,2012, p.8
While the criteria for the normality test are as follow : H
o
is accepted if Sig. p
value
α = 0.05 Ha is accepted if Sig. p
value
α = 0.05
b. Homogeneity Test
After the writer got the conclusion of the normality test, the writer done this homogeneity test to know whether the datas are homogeneous or not. The writer
used SPSS Statistical Program for Social Science to calculate the Levene‟s test.
The hypotheses for the homogeneity test are formulated as follows : H
o
= The variance of the data is homogenous H
a
= The variance of the data is not homogenous.
The criteria for the homogeneity test are as follows : H
o
is accepted if Sig. p
value
α = 0.05 H
a
is accepted if Sig. p
value
α = 0.05
1. Hypothesis Test
After the writer knowed that the datas are normal and homogeneous, the datas would be analyzed by using independent sample t-test in order to know the significance of
the treatment effect. The writer used SPSS Statistical Program for Social Science to calculate the independent sample t-test.
The hypothesis were:
H
a
: There is significant influence of brainstorming technique toward the students‟
descriptive paragraph writing ability at the eighth grade at MTs Yapenbaya Tajung Agung South Lampung in the academic year of 20152016.
H
o
: There is no significant influence of brainstorming technique toward the students‟ descriptive paragraph writing ability at the eighth grade at MTs
Yapenbaya Tajung Agung South Lampung in the academic year of 20152016. While the criteria for acceptance and rejection of the hypothesis were:
H
a
is accepted if Sig. α = 0.05
H
o
is accepted if Sig. α = 0.05
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