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CHAPTER III METHOD OF INVESTIGATION
This chapter discusses research design, sources of data, subjects, the experimental design, variable, instrument for data collection, construction of the
test, the pre test, the experiment, the post test, method of data analysis.
3.1 Research Design
In this research, the writer used experimental design with pre test of experimental group and control group. The think-pair-share strategy in experimental group and
conventional method in control group. The post test of experimental group and control group.
3.2 Sources of Data
In this research, some data are needed to achieve the objective of the research. The data and information are obtained from an experimental research conducted
in SMP N 1 Gabus, Purwodadi.
3.3 Subjects
There are two discussions here. They are population and sampling technique.
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3.3.1 Population
1 Population target group used in a questionnaire or interview study is that group about which the researcher is interested in gaining information and
drawing conclusion Tuckman, 1978:227. 2 Saleh 2001: 50 states that population is a group of people or objects
whose conditions are going to be discovered through the investigation. In this study, the writer decided to choose the seventh graders of SMP N 1
Gabus, Purwodadi in the academic year of 20092010 as the population. The total populations of VII A until VII G are 258 students. The choice of the subjects of
the study was based on the following considerations: 1 The students had been taught English since they were in elementary schools.
2 The students needed an interesting and enjoyable technique in learning English in general and especially in reading a descriptive text.
3.3.2 Sample and Sampling Technique
The sample is part or representative of population which is researched Arikunto 2006: 109. Sampling is an important step in conducting a research. The technique
of sampling has to be conducted in such away so that the sample represents the whole of population. In other word, the sample must be representative.
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The requirement of number minimum of sample: Population sample
Under 100 50
101-500 30 -50
501-1000 20 -30
Upper 1000 15 -20
Shaleh 2005: 50 As stated above, the total populations of this research are 258 students, so
the sample must be 30 -50 of total populations. To decide the sample, the writer used Simple Random Sampling. The followings are the explanation of the steps.
To decide experimental group, the writer made seven roll papers. A roll paper was named each class of seventh graders students of SMP N 1 Gabus,
Purwodadi, they are VII A – VII G. Then all the roll paper put in a box, then the writer shake the box until a roll paper fell down from the box, do it continuously
until get the result. To decided control group, the writer also used Simple Random Sampling
with the same steps. The results were, experimental group was VII G 39 students and the control group was VII E 39 students.
Thus, a conclusion is drawn that the sample are 78 students. Using Simple Randomly Sampling, the writer gets VII G with 39 students as an experimental
group using think-pair-share strategy and VII E with 39 students as a control group using conventional method.
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3.4 The Experimental Design
This study used “pre test-post test” control group and experimental group design. The design of the experiment could be described as follows:
E 01 X 02 C 03 Y 04
In which: E : Experimental group
C : Control group 01 : Pre-test for the experimental group
02 : Post-test for the experimental group 03 : Pre-test for the control group
04 : Post-test for the control group X : Treatment with the use of think-pair-share strategy
Y : Treatment without the use of think-pair-strategy
In the design above, subjects are assigned to the experimental class top line and the control class bottom line. The quality of the subjects is first checked by
pre-testing them O
1
and O
3
, then the experimental treatment is performed to the experimental class, while the control class is taught without using think-pair-share
strategy. The test consisted of one part, it is multiple choice tests. The result of which O
2
and O
4
then computed statistically.
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3.5 Variable
A variable can be defined as an attribute of a person or from an object. From the design of the experiment, two variables can be involved in this thesis.
1 Independent Variable.
Independent variable is the presumed cause of the dependent variable. In this experiment, the independent variable is cooperative learning used think-pair-
share strategy. 2 Dependent
Variable Dependent variable was the presumed effect of the dependent variable. The
dependent variable in this experiment is the students’ achievement in mastering reading, especially reading descriptive text.
3.6 Instrument for Data Collection
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