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c. The Testing of Statistical Assumptions
In this section, the researcher discusses the testing of statistical assumptions based on the data gathering and statistical study in this research. The
researcher analysed the testing of statistical assumptions into validity test, reliability test, normality test and hypothesis test. The researcher tested the
statistical assumption by using SPSS.v.21. Below is the data analysis which was
from the statistical study.
1 Validity Test
In order to test the validity, Pearson‟s Product-moment Simple Correlation r was used in this research. The test is used to test the validity of this research,
whether the data are able to reveal what is claimed to measure. In order to test the validity, the researcher compared the probability of Degree of Freedom DF = N
– 2 in the r
table
with the result of the test in the significance of 0.05 for two-tailed test. The validity test is valid if the validity value of the variable test is less than
the value of DF r r
table
. The validity test shows that the probability was 0.374 and based on the result, all of variables in X variable were less than 0.374.
Furthermore, the probability was 0.468 and based on the result, all of variables in Y variable was less than 0.468. Therefore, based on the validity test calculation of
the students‟ metacognitive learning strategies X and students‟ writing skills Y variable, it was valid because it shows that the validity level was 100. It means
that both variables were 100 valid. The result of the validity test is presented in Appendix 8.
65 2
Reliability Test The researcher used
Cronbrach‟s coefficient alpha to test the reliability of the students‟ metacognitive learning strategies X variable and students‟ writing
skills Y variable. The test is used to find out the reliability of both variables. The test is valid if the probability is larger than the r
table
r r
table
. Based on the reliability result, it is found that the reliability value was 0.920 with 0.444 for the
probability. In this research, the probability value was larger than the value in the r
table
, so it is found that the students‟ metacognitive learning strategies X variable and students‟ writing skills Y variable were reliable. The result of the
reliability test is presented in Appendix 9. 3
Normality Test In this research, the researcher used Kolmogorov-Smirnov test to test the
normal distribution of the variables. The test is used to compare the observed frequency distribution and the expected frequency distribution. It is found from
the normality test calculation of the students‟ metacognitive learning strategies X variable that the Kolmogorov-Smirnov Z value was 0.946 with 0.333 for the
probability. If the probability is larger than α = 0.05, it can be said that the variable distribution is normal. In this research, the probability value was larger
than α, so the distribution of the students‟ metacognitive learning strategies X variable was normal.
The researcher also used the Kolmogorov-Smirnov test to measure the students‟ writing skills Y variable and it was found that the Kolmogorov-
Smirnov Z value was 0.984 with 0.288 for the probability. Since the probability PLAGIAT MERUPAKAN TINDAKAN TIDAK TERPUJI
66 was larger than α, the distribution of the students‟ writing skills Y variable was
normal. Below is the result of normality test and the complete data is presented in Appendix 15.
Table 4.3 the Results of Normality Test
No Variable
Kolmogorov- Smirnov Z
Probability Conclusion
1. Students‟
metacognitive learning strategies
0.946 0.333
Normal 2.
Students‟ writing skills 0.984
0.288 Normal
4 Linearity Test
The researcher used regression analysis in order to test the linear relationship
between the students‟ metacognitive learning strategies X variable and students‟ writing skills Y variable. Based on the data analysis from the two
variables, it was found that the F value was 1.053 with 0.462 for the probability. If the probability is
larger than α = 0.05, it can be said that the variable distribution is linear. The result of the relationship between the two variables was larger than
α, so it can be said that it was linear. Below is the result of linearity test and the complete data are presented in Appendix 16.
Table 4.4 the Results of Linearity Test
F value p
Conclusion The relationship between
students‟ metacognitive learning strategies X variable and
writing skills Y variable 1.053
0.462 Linear
Based on the result of the calculation, the data from the two variables were normally distributed and the relationship was linear.
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