The Population and Sample

3.2 The Population and Sample

Gay 1987:102 says, “Population is the group of interest to the researcher, the group to which she or he would like the result of the study to be generalized.” It means that population is the total of objects or numbers that should be studied in the research. The data are collected from the sample of eighth year students who acted as the respondents of the research. In this case, the population is the eighth year students of SMP Negeri 11 Medan that consist of 420 students in twelve classes. Each class consists of 35 students. Furthermore, Sax 1987:180 states, “A sample is a limited number of elements selected from a population to be representative of that population.” It’s not all the population to be studied. In obtaining the sample, the writer used random sampling technique considering what Gay 1987:104 said that random is the best way to obtain a representative sample. Arikunto said 1993:120 who says that the sample can be taken from 10-15 or 20 - 25 more, it depends on the ability of researcher by considering her time, energy and funds. For the efficiency and practically of the research, only eighth year students are chosen randomly to the represent the whole population. Yet in this case, the writer chooses two classes or 70 students. 3.3 Instrument of Collecting Data The instrument of collecting data is such devices used by the researcher in collecting Data. In this research, the instrument of collecting data is a test composed by researcher. The test is in the form of essay to gain the data or information which is used to analyze the students’ achievement in vocabulary. Universitas Sumatera Utara Pre Test : is the measurement of the dependent variable prior to introduction of the treatment the students are given essay test before the teacher gives them the treatment in the control group and the experimental group. Post Test : is the measurement of dependent variable after the treatment has been introduced into the experimental group the students are given essay test after they are given the treatment. Control group is given post test by using conventional method and experimental group is given post test by using treatment of word square method. The test consists of 20 questions which are related to vocabulary. The test is divided into 3 sections I,II,III. Section I consists of 10 questions, it is about animals and plants. Section II consists of 5 questions, it is about the things that can find in First Aid Kit Box. Section III consists of 5 questions to complete the paragraph. The test is arranged like that to make variation for the students in answering the test. The test is adapted from the text book of Curriculum for 8 th year students.

3.4 Technique of Analyzing Data