Research Design METHOD OF RESEARCH

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3.3 Population and Sample

Arikunto 1993:102 says, “Population is the whole number of the subject or people under observation in research.” In this research, the population is the grade XI students of SMA Cahaya Medan that consist of 42 students in grade XI IPA 1, 45 students in grade XI IPA 2, 45 students in grade XI IPA 3, 44 students in grade XI IPS 1, 45 students in grade XI IPS 2, and 46 students in grade XI IPS 3. The total of population in grade XI of SMA Cahaya are 267 students. For limited the time, the data of all population can not be analyzed but some of them can be taken as a sample which has represented the student’s ability. Arikunto 1993:109 says, “A sample is a limited number of elements selected from a population to be representative of that population”. Random sampling is used to gives students a chance of being selected as the sample. As Gay 1987:104 states, “Random sampling is the best single way to obtain a representative sample. This procedure guarantees a higher probably than any other way.” and Lado 1961:20 says, “The sample should ordinarily be randomly selected.” Then it is decided to take them in random sampling by lottre. In this study, there are 6 classes of SMA Cahaya Medan students in grade XI and it was choosen 60 students as sample about 25 of population. It is considered representative enough and relevant as Arikunto 1993:107 said that the size of sample is 10-15 or 20-25 the population is relative large. It was choosen 30 students from XI IPA 3 and 30 students from XI IPS 1 at random. Here are the following table of sample in grade XI SMA Cahaya Medan students. 35 Table 3.1 Distribution of Research Population No. Class Number of Students 1. XI IPA 3 30 2. XI IPS 1 30 TOTAL 60

3.4 Data Collection Procedure

According to Wikipedia, “Data is a set of values of qualitative or quantitative variables; restated, pieces of data are individual pieces of information. Data is measured, collected and reported, and analyzed, where upon it can be visualized using graphs or images.” It means that the data is instrument for researcher to measure, reported and analyzed the problems to be information to solve the problems. Based on the explanation, it is needed some baseline data that represent student’s ability with giving them a test about conditional sentences. It was done by the grade XI students of SMA Cahaya Medan by giving them 15 items of multiple choice and 15 items of completion test. In scoring the test, it was given one point for one item. So, there are 30 items which was conducted in 60 minutes. It is enough because Lado 1961:20 says, “We must test in one hour what has been learned in a month or a year or five years”. Then, the researcher arranged the instrument of research as follows : 1. Test on the use of Future Conditional, number 1,2,3,4,5 in multiple choice and completion test.