something that must be measured.
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To measure whether the test had good validity or not, the researcher used content validity and construct validity. They are:
a. Content Validity
According to Setiyadi, content validity associated with all the items contained in a measuring instrument.
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It means that, to get content validity the test would be adapted with an English teacher and the students‟ book that the test appopriate with the
material taught to the students. In other words, the researcher made the test based on the material in 2006 of English curriculum for Senior High School.To know whether
the test has a good validity, the items of the test were discussed with the expert the English teacher of SMAN 1 Ambarawa Pringsewu.The result of the content validity
stated that all items of the test were made based on material in 2006 of curriculum for senior high school and the syllabus can be seen on appendix 30.
b. Construct Validity
Construct validity is the extent to which the data collection instrument provides scores that can be used to make inferences about a construct.
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It means construct validity concerned with whether the test is actually in line with the theory or not.
Then the items should really show whether they have conditional sentence that has
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Ag. BambangSetiyadi, MetodePenelitianuntuk Pelajaran Bahasa Asing Pendekatan Kuantitatif dan Kualitatif, Yogyakarta: GrahaIlmu, 2006,p.22
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Ibid, p.23
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James Schreiber Kimberly Asner-Self, Educational Research, USA: John Wiley Sons, Inc, 2011, p .114
been taught or not, and should really measur e the students‟ conditional sentence
mastery. To know whether the test have a good construct validity, the items of the test were consulted to the English teacher of SMAN 1 Ambarawa Pringsewu. The
result of the construct validity stated that the items were ready to be tested because it has a good construct validity.
c. Item Validity
Item validity is used to measure whether the items of the test are valid or not. In this research, the researcher used Anatestto calculate the data which was taken from the
try out. The try out was conducted on September 27
th
2016 and September 28
th
2016. The try out was given to the students in XI IPS 1class. It was done to find out the
item validity of each items.
Based on the callculation by using Anatest, 25 items of the 40 try out items for pre test were valid. They were item number 1, 2, 3, 4, 5, 9, 10, 11, 12, 13, 14, 15, 16, 18,
19, 23, 25, 27, 28, 31, 32, 33, 34, 39, and 40. While for the items for post test, there were 25 items of the 40 try out items for post test were valid 1, 4, 5, 6, 7, 8, 9, 12, 14,
15, 16, 20, 22, 23, 25, 26, 27, 29, 30, 31, 32, 33, 37, 38, 40.
