First element that is used to measure the test is validity. There are many types of validity such as content validity, construct validity, and
criterion validity.
4
The type of validity that is used in this research is construct validity. To examine the construct validity, the judgment
experts is used. In this case, the researcher has already consulted the test with her advisor and an English teacher at school where she did
the research. 2. Reliability
The second element is reliability. Reliability refers to the extent to which test scores are free of measurement errors.
5
In this research, the analytic scoring is used. The analytic scoring is one of many types of
rating scales in measuring writing. “In analytic scoring, scripts are rated on several aspects of writing or criteria rather than given a single
score.”
6
F. The Technique of Data Collecting
Written test is the only one technique that used by the researcher in this research. Giving the explanation about writing essay to both of classes,
the experimental and the control class, is the first step that the researcher do to collect the data. Then they were asked to write an essay.
The test which is the only instrument of this research was about writing analytical text using essay form. The students were asked to write
everything which they interesting about and make the analytical reason of it. It was also considered from the current material which is studied by all of
them in their English language subject. The scoring of the test is focused on their ability in using mind
mapping and how they generate ideas from general one to the details. Other
4
Muijs, Op.,cit., p. 66
5
Ibid., p.71
6
Sara Cushing Weigle, Assessing Writing. New York: Cambridge University Press, 2002, p.114
assessments can be looked from their skill in writingthat looked specifically from these points of assessing:
a. Content b. Organization
c. Vocabulary d. Language Use
e. Mechanics
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Those five points are widely used in ESL which is created by Jacobs et.al. The creator differentiates the weight of scoring for every aspect such as
content consist of 30 , organization consist of 20, vocabulary 20, language use consists of 25, and mechanics consists of 5 point out 100.
G. The Technique of Data Analysis
The technique of data analysis used in this experimental research is t- test formula. The use of t-test formula is to examine the hypothesis of the
research after collecting the data in this experimental research. Here are the technique and steps of data analysis:
1. Determining mean of gained score of experimental class M =
Notes:
M : Mean of gained score of experimental class X: The total gained score of students in the experimental class
N: The total students in experimental class 2.
Determining mean of gained score of controlled class =
: Mean of gained score of controlled class
7
Ibid, p.115.
