s : Standard deviation ̅ : Coefficient of single datum
x
i
: Single datum The criteria as a follows:
H
o
is accepted if L
o
L
c
Sig α = 0.05 H
a
is accepted if L
o
L
c
.= 0.05
18
2. Linearity Test
Linearity test is used to know the size of the linear relationship between two variables x and y. Before analyzing the data by using pearson’s product moment
formula, the writer checked out whether the data obtained were linear or not, because this is one of requirements to be able to use t
he pearson’ product moment formula. The writer used SPSS Statistical Program for Social Science to check it in order to
make the writer easy. Then, the writer checked the result of linearity by comparing with significant leve
l α = 0.05. If the result is lower than α, it means that the data were linear. The significant level of linearity test was 0.000, it means that the data
was linear see Appendix 25
3. Hypothetical Test
The hypothesis is very important to find out whether or not the null hypothesis H
o
or alternative hypothesis H
a
is accepted in this research.
18
Sugiyono, Pengantar Statistik Pendidikan, Jakarta; Rajawali Press,1
st
Ed, 2009, p.78
The following are the steps in measuring Product Moment coefficient of correlation.
19
a. Formulating alternatives hypothesis H
a
and null hypothesis H
o
. 1 Measuring Product Moment coefficient of correlation of variable X and Y by
using formula
20
: г=
∑ ∑ ∑ √{ ∑
∑ }{ ∑
∑ }
Notes: ∑
: sum of the X score ∑
: sum of the Y score ∑
: sum of the squared students’ adjective mastery score
∑ : sum of the squared
students’ writing descriptive ability score ∑
: sum of the products of paired X and Y scores N
: number of paired score
The hypotheses are: Ho
= there is no correlation of students’ mastery in using adjective and their
ability in writing descriptive text. Ha
=there is correlation of students’ mastery in using adjective and their ability
in writing descriptive text.
This is criteria of hypothetical test:
19
Anas Sudijono, Op.Cit., p.194-195.
20
Suharsimi Arikunto,Op.Cit.,p.317
