J. Validity, Reliability, and Readability of the Test
1. Validity of the Test
Validity is the most important idea to consider where preparing or selection an instrument for use.
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An instrument can be said valid when it can measure what it wants to measure. In other words, an instrument can be said valid if it can show the
data of variables that are being research correctly. To know the validity of the test, it was provided content, construct and internal validity. In this case, the validity of the
test was calculated by using anates. Anates is application program capable of calculating the analysis for multiple choice and essay of items quickly, easily and
accurately.
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It means that anates is used to calculate the validity of the test for multiple choice and essay of items quickly, easily and accurately.
a. Content validity
Best and Kahn say that content validity refers to the degree to which the test actually measures, or is specifically related to, the traits for which it was design, content
validity is based upon the careful examination of course textbooks, syllabus, objectives, and the judgments of subject matter specialists.
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It means that the content validity is based on the material, and the material is agreement with the objectives of
learning. To get the content validity test, it was tried to arrange the material based on
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Jack R. Fraenkel and Norman E. Wallen, Op. Cit, p.147
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Muchammad Aruf, Jurnal Ilmiah: Penerapan aplikasi ANATES, Madura: Universitas Trunojoyo Madura, 2014, p. 5
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John W. Best and James V. Kahn, Research in Education 7
th
Ed, New Delhi: Prentice- Hall, 1995, p. 219
the objectivitas of teaching in the school based on curriculum for eight grade of SMPN 1 Karya Penggawa Pesisir Barat. The syllabus could be seen in Appendix 3.
b. Construct validity Best and Kahn say that Construct validity is the degree to which scores on a test can
be accounted for by the explanatory constructs of a sound theory.
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It means that construct validity is focused on the aspects of the test which can measure the ability
especially for writing descriptive text and simple present tense mastery. In this research, a writing descriptive text test and simple present tense mastery test was
administrated with considered the scoring covers five aspect of writing descriptive test they are, content, organization, vocabulary, language use, and mechanics. Scoring
covers four aspect of simple present tense test has three aspect they are, nominal sentence, verbal sentence, and time signal in positive, negative, interrogative, and
negative interrogative form.
In this research, a descriptive text test that was made to the measure the students’
ability writing descriptive text based on the scoring system by Christopher Tribble. To make sure, the instrument was consulted the to the English teacher of SMPN 1
Karya Penggawa. The teacher is Melda Wati, S.Pd to make sure the validity of the test is valid.
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Ibid.
The validity of simple present tense mastery sheet and writing descriptive text sheet were given to the English teacher as a validator. Validity was conducted in order to
see clarity of the aspect, direction of the test and to see clarity of the items. The consultation was conducted before the try out that was held on September 30
th
, 2016. The English teacher said that the instrument or items covered each aspect in the test
10 specification in simple present tense mastery test. Each of the items also was suitable with the aspect in simple present tense mastery test, it can be seen in
appendix 8 and 9.
c. Internal Validity Internal validity is observed differences on the dependent variable are directly related
to the independent variable, and not due to some other unintended variable.
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It means that internal validity is used to evaluated whether variables affect each other.
To determine whether variables affect, the writer needs to do a treatment try out.
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In this research, try out the test was conducted on October 7
th
, 2016. The try out the test was prepared in form of multiple choice questions in 50 items of simple present tense
mastery test. The result of validity analysis shows that there were 40 items from 50 items.
Based on the result obtained in the anates, the result of validity test for simple present tense mastery test showed that there were 40 items considered valid they were 1, 2, 3,
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Jack R. Fraenkel and Norman E. Wallen, Op. Cit, p. 166
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Ag. Bambang Setiyadi, Op. Cit, pp. 126-127
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