O4 is post – test for the controlled group
X is treatment for experimental group
2
using picture storybook
In this design, there are two observation; those are before and after experiment. Those observation called pre
– test, and post – test, in which pre – test is the observation which is conducted before the experiment and post
– test is the observation which is conducted after the experiment. In this design, there are two
groups of students as the samples. At the first time, both of groups are given pre – test
in order to know their competence in vocabulary mastery before they are given a treatment. In the experimental group, they will get a treatment by using picture
storybook, while the controlled group, they will get a treatment by using conventional technique.
C. Population and Sample
The population of this research is the seventh grade students at junior high school Kartika VIII-1 Cijantung for academic years 20162017. The seventh grade students of
this school for academic years 20162017 are 199 students, and they are divided into six classes 7
th
A, 7
th
B, 7
th
C, 7
th
D, 7
th
E, 7
th
F. For selecting samples, the writer gets recommendation class from the English teacher at this school. Because the samples in
this study are lack of vocabulary, they are hard to be controlled in the class, and they are difficult to understand a material easily. It means that this research uses purposive
sampling. According to Fraenkel, Wallen, and Hyun about purposive sampling, they said investigators use personal judgment to select a sample based on prior knowledge
of a population and the specific purpose of the research.
3
In the research, the writer involves 60 students at seventh grade as the samples, 30 students are experimental
group, and 30 students are controlled group.
2
Sugiyono, Metode Penelitian Pendidikan, Bandung; Alfabeta, 2015, p. 116.
3
Jack R. Fraenkel, Norman E. Wallen and Hellen H. Hyun, How to Design and Evaluate Research in Education Eight edition, New York: McGraw-Hill Higher Education, 2012, p. 100.
D. Research Instrument
The research instrument that the writer uses to collect data is test. The test is divided into two parts: pre-test, that is given to both experimental and controlled class
before treatment, and post-test, that is given to both classes after the treatment. The test have 30 questions about vocabularies around
students’ life that focus on noun and adjective.
Before the test is administered, the reliability and the validity of the test will be analyzed to find out whether the test is good to be used or not.
E. Technique of Collecting Data
Collecting data is the most important step in conducting the research. The types of test that the writer uses are multiple choice, matching task and picture cued task.
The questions of the test are about things around students’ life, and those questions
are tested to another group, which is not including as sample of the research, to see the reliability and validity of instrument. The writer analyzes the result of it by using
Anates. Then, the writer collects 30 questions for pre-test, and the writer randomizes those questions for post-test. The writer gives the valid questions to experimental and
controlled class for the pre-test and post-test. By this activity, the writer gets the scores about stude
nts’ vocabulary mastery that will be analyzed. In this research, the writer uses some steps for experimental class, as the
following: Day-1
a. Teacher asks student to make a group consist 4-6 people of each group
b. Teacher introduces picture storybook for the first time to experiment group.
Teacher reads the title, the writers and the publisher of the picture storybook. c.
Teacher shows the cover and asks students to make a simple prediction about the story that will be read by the teacher.
d. Some groups will delegate a representation of them to write their prediction on
the white board.
