28
b Reliability of Instrument
“Reliability means that scores from an instrument are stable and consistent. Scores should be nearly the same when researchers administer
the instrument multiple times at different times.”
7
The researcher used SPSS 20 in order to know the reliability of questionnaire. The result can be
seen as below:
Table 3.4 The Reliability of Questionnaire
The result shows that r
result
= 0.932. In comparing to r
table
with N=35 and 5 as significant level, that is r
table
= 0.334, it can be concluded that the instrument is reliable because r
result
r
table
= 0.932 0.334. 2. Documentation
The definition of achievement in this research is the result of what the students has learned. In this research, English learning achievement is taken from
the scores that the students obtained in learning English after they have followed teaching-learning process in English subject at the school. Thus, the writer took
the score from the report book of eighth grade students class C of SMP Ibu Pertiwi for second semester in academic year 20142015 to be analyzed.
E. The Data Analysis Techniques
After getting data from the students in the questionnaire, the writer needs to analyze the data and correlate the questionnaire score and
the students’ English achievement score.
In analyzing the data of the relationship between parents’ involvement and
s tudents’ English achievement, the researcher used correlation product moment
7
John W. Cresswell, Educational Research, Boston, Pearson Education Inc., 2012, p. 159.
Reliability Statistics
Cronbachs Alpha N of Items
,932 35
29
which developed by Carl Pearson. ” Correlation product moment is used to show
whether there is a correlation between X variable and Y variable”.
8
Data operation technique is done through the steps below:
1 Finding the number of correlation using formula: ∑ ∑ ∑
√ ∑ ∑
∑ ∑
Note : r
= Coefficient of correlation between X variable and Y variable N
= Number of respondents ∑XY = The sum of the multiplied of X and Y
∑X = The sum of X scores parents’ involvement ∑Y
= The sum of Y scores students’ English achievement
∑X² = The sum of quadrate of each X scores ∑Y² = The sum of quadrate of each Y scores
∑X² = The sum of the quadrate of ∑X scores ∑Y² = The sum of the quadrate of ∑Y scores
Significant critical value : 0.05 and 0.01
This formula is used in finding index correlation „r’ product moment between X variable and Y variable r
xy
.
8
Budi Susetyo, Statistika untuk Analisis Data Penelitian, Bandung: PT Refika Aditama, 2010, p. 121.
30
2 After the r was found then the writer interpreted the correlation based on following level of correlation.
Table 3.5 The Level of Correlation
9
Product Moment r Interpretation
0.00 – 0.199
Very Low Correlation 0.20
– 0.399 Low correlation
0.40 – 0.599
Moderate Correlation 0.60
– 0.799 High Correlation
0.80 – 1.000
Very High Correlation
3 To know the significance between two variables, the formula of the significance test is:
10 √
√
Note: = t value
r = value of correlation coefficient n = number of participants
F. Statistical Hypotheses
To know whether there is any significant correlation or not between X variable and Y variable, the writer formulated H
a
Alternative Hypothesis and H
o
Null Hypothesis first as follows: a Alternative Hypothesis H
a
: there is significant correlation between X variable parents’ involvement and Y variable students’ English learning
achievement
9
Sugiyono, Metode Penelitian Pendididkan: Pendekatan Kuantitatif, Kualitatif dan RD, Bandung: Alfabeta, 2013, p. 257.
10
Susetyo, op. cit., p. 123.
31
b Null Hypothesis H
o
: there is no significant correlation between X variable parents’ involvement and Y variable students’ English learning
achievement Some assumptions are as follows:
a If the result of calculation r
xy
is smaller than r
t
r table, r
xy
≤ r
t
; so the null hypothesis H
o
is accepted H
a
is rejected. b If the result of calculation r
xy
is bigger than r
t
t table, r
xy
≥ r
t
; so the null hypothesis H
o
is rejected H
a
is accepted.
