CHAPTER III METHOD OF INVESTIGATION
3.1 Object of the Study
3.1.1 Population and Sample Population is a group about which the researcher is interested in gaining
information and drawing conclusion Saleh, 2004:227. The population of this study is the eighth grade of SMP N 26 Semarang in the academic year of 2007-
2008. The writer chooses students of the eighth grade as the population because they have ever been taught English from seventh grade; so they have had basic
competence in learning English. A sample is a group of people, thing or place where data is collected. A
sample is actually a part, which is considered as a representative of a population Saleh, 2001:33. In this study, the writer selected two classes of the students from
population as sample. In order to get the representative sample, the sample should represent the true situation of the population. They are experimental group, which
were taught by using pictures, and control group, which were taught without using pictures in improving descriptive writing skill. The are two classes chosen from
the six classes of the eighth grade student of SMP N 26 Semarang.
3.2.1 Experimental Design An experimental research involves two groups, an experimental group and
controlled group where the experimental group typically receives a new, or novel,
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treatment, or has treatment under investigation, while the controlled group either receives a different treatment, or is treated as usual. The design of the experiment
can be described as follows:
04 03
C 02
X 01
E −
Where : E : Experimental group
C : Controlled group
01 : pretest for the experimental group
02 : posttest for the experimental group
03 : pretest for the controlled group
X : Treatment with pictures as an aid
Arikunto, 2002:79 It can be explained that subject are assigned to the experimental group two
line and control group bottom line. The writer will check the quality of the subjects first by giving a pretest 01 and 03, then give the experimental treatment,
in this study, is taught descriptive writing skill by using pictures as an aid, to the experimental group, while the controlled group is taught without pictures as an aid
in this research by using explanation.
3.1.3 Research Variable A variable is a property that takes on different values. In this experimental
research, there are two variables, independent and dependent variable. Kerlinger 1973:35 states:
“The most important and useful way to categorize is as independent and dependent. This categorization is highly useful because of its general
applicability, simplicity, and special importance in conceptualizing designing research and in communicating the result of research.”
This experiment, which uses pictures as teaching aids in improving descriptive writing skill, has two variable. They are an independent variable and a
dependent variable. Here, the independent variable is the method of teaching a descriptive writing skill using pictures as teaching aids. The independent variable
is the students achievement manifested in the test score.
3.2 Instrument
Kategori