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independent variable is the variable selected by the researcher to determine the relationship with the dependent variable.
In this study, the variables were: 1 Independent Variable: The use of team-pair-solo in reading comprehension
2 Dependent Variable: The students’ achievement in reading comprehension test The students that became the object this study were the students of senior high
school.
3.4 Instrument of the Study
According to Azwar 2010: 34, an instrument used to measure the research variables runs an important role in trying to collect accurate and credible information. Besides,
the importance of instrument is also stated by Kerlinger 1965:48. He states that instrument is an important device for collecting the data in a research study.
Therefore, it can be inferred that instrument is needed to collect the data. Besides, he also states that for the most part, the instrument used to measure the achievement in
education is a test. Therefore, I used a test method as the instrument for this research.
3.4.1 Tests
As stated by Brown 2004:3, a test can be defined as a method of measuring a person’s ability, knowledge, or performance in a given domain. As a method, it is an
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instrument—a set of techniques, procedures, or items that requires performance on the part of the test-taker.
In this research, I used one type of test which was a multiple-choice completion. This type of test was chosen mainly because of practicality Brown,
2004:19 in which it is easy to administer and can be scored quickly. Furthermore, for this test is to assess the students reading comprehension, the
test items used in this research are made based on the reading comprehension aspects for senior high school students. Those aspects are scanning, vocabulary knowledge,
topics, topics of paragraph, main idea, patterns of organization, making inferences, and skimming.
Besides, the test items were also made based on Bloom Taxonomy. Items of the test can be classified into six terms. Those terms are remembering, understanding,
applying, analysing, evaluating, and creating.
3.4.2 Try-out
A test can be said as a good test if it is valid and reliable. Therefore, the test that would be tested to the students should be valid and reliable too. The suitable way to
make a good test is done through try-out. Try-out was done before the test was administered to know the validity and reliability of the test items. From the results of
try-out, it could be seen which items should be used in the test. In this research, try out was done twice. The first was done for the pre-test, while the second one was for
the post-test.
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3.4.3 Validity
Based on the definition stated by Gronlund, 1998:226, validity is the extent to which inferences made from assessment results are appropriate, meaningful, and
useful in terms of the purpose of the assessment. The formula of the validity is as follow:
Where, r
xy
= the validity of the item test N
= the number of the students X
= the number of students who answer correctly Y
= the students’ score
3.4.4 Reliability
