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CHAPTER III
METHODOLOGY
A. Place and Time of study
To collect the data, the research took a place in the SMPN 239 Jakarta. This school is located in Lenteng Agung, South Jakarta. The writer chose this school
because the writer already knew the students’ knowledge about English. The writer started the research on October 2015. The writer held the research in the
English class.
B. Method of Research
This study involves two variables namely joining English Course and students’ English achievement. In this study, the writer used a quantitative
method with the correlation method. The writer used Point-Biserial Correlation Coefficient which is a correlation measure of the strength of association between
a continuous-level variable ratio or interval data and a binary variable. Binary variables are variables of nominal scale with only two values. The writer used
SPSS to analyze the research with the formula;
Where: rpbi = point-biserial correlation coefficient.
Mp = whole-test mean for students answering item correctly. Mq = whole-test mean for students answering item incorrectly.
St = standard deviation for whole test. p =
proportion of students answering correctly. q =
proportion of students answering incorrectly.
C. Population and Sample
The writer took the population of the third grade students of SMPN 239 Jakarta with about 360 students. The writer chose the third grade class E of this
school that consists of 34 students as the sample. In the students’ distribution, the
writer distributed students randomly or used simple random sampling, and it is not based on the level of students’ competency. Based on Creswell, in simple random
sampling, the researcher selects participants or units, such as schools for the sample so that any individual has an equal probability of being selected from the
population,
1
the writer chose the sample because they are already in the third grade of junior high school and will face a national exam in few months ahead.
D. Data Source
The writer used open-ended and close-ended questionnaire for the English Course variable. The variable
students’ achievement obtained from the score of English examination in order to prepare the national exam made by school
teachers of English as the secondary data.
1
Creswell, John W. Educational research : planning, conducting, and evaluating quantitative and qualitative research John W. Creswell. Boston: Pearson Education, Inc., 2012,
p. 143.
E. Technique of Data Collecting
Techniques of collecting data in this research are using documentation and questionnaire. Variables of
‘English course’ used a questionnaire and variables of students’ English achievement is students’ score of English test. The further
explanations of them are as mention below; 1.
Documentation T
he students’ English test score is needed for the documentation data. The result of the test was already conducted by the English teacher in the school.
2. Questionnaire
The writer used a closed-ended questionnaire. Open-ended questions provide an opportunity to the respondents to answer according to what they want. While in
the closed questions, respondents chose the ‘yes or no’ answers that have been
provided in the questionnaire, the respondents could not provide the answer freely.
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F. Technique of Data Analysis
The next step the writer does is analyzing the data. The writer analysis the data by using statistic calculation of Point Bisserial Correlation. The Point-
Biserial Correlation Coefficient is a correlation measure of the strength of association between a continuous-level variable ratio or interval data and a
binary variable. Binary variables are variables of nominal scale with only two values. The writer used SPSS software for analyze the data. The writer also used
Sugiyono’s Correlation Interpretation Table see Table 3.1.
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ibid., p. 220
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