Place and Time of the Research Research Design
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a Validity of Instrument
“Validity refers to the degree to which a test measures what it is supposed to measure and, consequently, permits appropriate interpretation
of scores.”
6
Validity test is very important in all forms of research because validity is the criteria of good instrument. In validating questionnaire, the
researcher conducted the research in 8-A class of SMP Ibu Pertiwi, Jakarta Barat. The researcher got the standard coefficient validity minimum for
this instrument with N = 35 and coefficient validity is 0.334. To see the validity instrument, the researcher use SPSS 20 to measure the validity of
questionnaire. In the questionnaire validity, the writer got 26 items from 35 items.
The number of valid item are 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 16, 23, 17, 19, 20, 22, 24, 26, 27, 28, 30, 31, 34 and 35. The items that the researcher
used only 25 items which can be seen as below:
Table 3.3 Valid Items of Parents
’ Involvement
No Indicator
Item Number
1
Home Discussing school activities
1, 2, 2
Aspiration and expectation 3, 6, 22
3 Parenting Style
4, 5, 24 4
Reading at home 7, 8, 9, 26
5 Checking homework
10, 11, 30 6
Home rules and supervision 19, 20, 34
7 School
Contacting school personnel 13, 27
8 Attending PTO, etc.
31, 35 9
Volunteering at school 16, 17, 28
Total 25
6
L. R. Gay, Geoffrey Mills and Peter Airasian, Educational Research, New Jersey: Pearson Education Inc., 2009, p. 154.
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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.