Research Hypothesis THEORETICAL FRAMEWORK
the writer teaches on both of class experimental class and controlled class and post-test was given at the end of the reserach.In order to get a good instrument, it
would be continuouslly tested through validity and reliability test. A valid test measures and accurately reflect what it was designed to
measure. According to Brown, validity is the extent to which inferences made from assessment results are appropiate, meaningful, and useful in terms of the
purpose of the assessment.
5
Validity is related to knowing the exact purpose of an assessment and designing an instrument that meets that purposes.
6
So, before this instrument is applied to the students as the sample of the this study, the instrument
would be tested to students in different class in the same grade. The writer took two classes, VIII E and VIII F.The analysis of this instrument was done to see the
validity using the formula of item analysis in test using Statistical Package for the Social ScienceSPSSversion 22. To compute data, the steps were as follows:
a. Open the IBM SPSS Statistics 22 b. Go to variable view and fill in the columns as follows.
1 Name Write Q.1 for question number 1 untill Q.35 for question number 35
2 Type column was numeric 3 Width column is filled 8
4 Decimal change this row frow 2 to 0 5 Label column was left blank
6 Value column is none 7 Missing column is none
8 Column is 8 9 Align column is right
10 Measure coulumn is unknown 11 Role coulumn is filled with input
c. Click Data View, in each Q column, compute 1 to correct answer and 0 to incorrect answer.
5
H. Douglas Brown, Language Assessmentnew York: Longman, 2004, p. 22
6
JoAnne Schudt Caldwell, Comprehension Assessment, New York: The Guilford Press, 2008, p.29
d. Click AnalyzeScaleReliability Analysis e. Transfer the data from the left rectangular to the right rectangular
f. Click statistic g. Ceklist Scale if item deleted in Desciptive for option
h. Ceklist none in ANOVA Table i. Click Continue then O.K
After the steps have done, there was output. TheCorrected Item Total Correlation is represent r
hitung
for each questions. The validity and reability can be seen from r
table
and r
hitung.
If
.
r
hitung
r
table
, it means that the items mighht be used. The criteria of validity.
0.80r
xy
≤1.00 very high
0.60r
xy
≤0.80 high
0.40r
xy
≤0.60 enough
0.20r
xy
≤0.40 low
0.00r
xy
≤0.20 very low
r
xy
≤0.00 not valid
The writer also pay attention to reliability test. A reliable test is consitent, that is yields similar results over time with similar students in similar situation.
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It also stated by Bartlett and Diana Burton that reliability describes the extent to
which a research instrument or method is repeatable.
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It is clear that, the reliability test is necessary to be tested before the instruments will be given to the sample of
the study. The steps that must be done was same with analyze the validity. In output
of the analysis, it would be foung Reliability Statistics. In the left column, there was
Conbarch’s Alpha. It is an internal consistency score based on ekuavalen of each item that represent reliability. Both validity and reliability have the same
criteria.
7
JoAnne Schudt Caldwell, Comprehension Assessment, New York: The Guilford Press, 2008, p.30
8
Steve Bartlett and Diana Burton, Introduction to Education Studies, London: SAGE Published, 2007 p. 44