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3.3 Instrument for Collecting Data
In a research, instrument is an important device to collect the data. The instrument was used to measure the students’ ability. In this study, there were three stages to
collect the data: pretest, treatment, and posttest. Before the test was given, the researcher gave try out test.
3.3.1 Try - Out
A test can be said as a good test if it is valid and reliable. So, before doing the test, the researcher gave try out test. Try out was necessary to measure validity and
reliability of the test. As the result, try out was to prove whether the instrument was good or not. In this research, try out test was done once in other class. The
respondents of the try out test were the students of class X-4 of SMA Islam Sultan Agung. The students were asked to make descriptive texts of their best friends in
50 minutes. The length of paragraph was about 15 until 20 sentences.
3.3.2 Criteria of the Test
A test can be said well if it demands some qualities such as validity and reliability. 3.3.1.1 Validity
Validity is one of necessary formulas to measure the instrument. Based on the statement of Arikunto 2006:168, “validity is the measurements that indicate the
validity level of instrument”. In this study, the researcher used try out test based on the curriculum and materials that have been given to the students so far.
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3.3.1.2 Reliability Another characteristic of a good text is reliability. Based on the statement of
Arikunto 2006:178, “reliability is determined by the carefulness of evaluation instrument and important of reliability consistence, how far of the test or
instrument can be believed”. It means the reliability of the test score will give the same result when the test is used in different time. In this study, the researcher
used interrater reliability. There were two raters. First rater was the researcher and the second one was the English teacher.
3.3.3 Pretest
There are two groups for doing experimental research. They are experimental group and control group. Both of groups were given different treatment but the
same material. The experimental group was photograph in Facebook as treatment and for the control group was only taught in conventional teaching.
A pretest was given before the treatment. The pretest for both the experimental and control group was given on 28
th
April 2013. There are 33 students for each class. The researcher came into the class and gave the
instruction. The students were asked to write descriptive texts about their best friends in 50 minutes. The length of the paragraph was about 15 until 20
sentences.
3.3.4 Treatment
The treatment was given before the posttest conducted. The students for both classes were taught some materials about descriptive text. The treatments were
conducted twice for each group. The first treatment was held on May 5
th
and 12
th
25
2013. For the experimental group, the researcher used photographs in Facebook as media. The researcher gathered the students into one group in Facebook account.
He put some materials in the group. The students of the experimental group also could do online for learning their materials by opening their Facebook account
whenever they wanted. For the control group, the researcher only did conventional teaching. He only gave some materials about descriptive text. The
students were not given photographs in Facebook as media.
3.3.5 Posttest
Posttest was the last step for collecting data in experimental research. It was held on 19
th
May 2013 for the control group and May 22
nd
2013 for the experimental group. The test given was the same as the pretest.
3.4 Scoring Technique
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