Method of the Study Procedure of Inventing

4 Technique of Data Collecting the writer used the test to collect the data. The pre-test and post-test waas given in both of the two classes. The pre-test was given before the writer began the teaching and learning process in two classes. Meanwhile, the post- test was given in order to know the students’ improvement in mastery vocabulary. The pre-test and post-test are multiple choice form and it was consists of 20 items. The teacher gave 30 minutes in both of the two classes for finishing pre-test and post-test. 5 Technique of Data Analysis The writer has conducted the test; pre-test and post-test. The data is compared from the mean of the score from pre-test and post-test. After getting the data from the score, then the data was analyzed and processed by using statistic calculation of T-test formula with significance degree 5 and gained scores. T-test in this research used to test the average difference count, was there a significant difference or not between the experimental group and the control group. While the gained score is the difference between pre-test and post-test score of each class of the experimental and the control groups. Gain scores are used to determine the increase or decrease in scores and to determine the effectiveness of the media used. However, prior to the tests the hypothesis necessary analysis prerequisite tests first, namely the distribution normality test and homogeneity test. 1. Pre requisites Test Analysis a Normality Test Population Normality test data and research using chi squared using the following formula by Riduwan 5 � 2 = ∑ �� − �� 2 �� Specification: X 2 = value of chi-squared Fo= frequency obtained based on the data Fe= the expected frequency frequency theoretical Normality testing criteria: If X 2 o ≤ X 2 t, so the data distribution are normal. If X 2 o ≥ X 2 t, so the data distribution are not normal. b Population Variance Homogeneity test Homogeneity test is conducted to determine whether the both of groups have the same variant or not homogeneous or not. According to Riduwan 6 test in this research using Barlet test with significance level α = 0.01, with db1= N1 -1 and db2 = N2 -1. � = �ℎ� ������� ������� �ℎ� �������� ������� Terms Homogeneous: If Fo ≤ Ft, then Hois accepted homogeneous and Ha rejected. If Fo ≥ Ft, then Ho is rejected not homogeneous and Ha accepted. 5 Riduwan, Belajar Mudah penelitian unttuk Guru, Karyawan, dan Peneliti Pemula, Bandung: ALFABETA,2011, p.121. 6 Ibid. P. 119 c T-test According to Sudjiono that the formula is follows: 7 t ₒ = M 1 − M 2 SE м 1 − м 2 M 1 : Mean of the Difference of Experiment Class M 2 : Mean of the Difference of Control Class SE M 1 : Standard of Error of Experiment Class SE M 2 : Standard of Error of Control Class In order to get the calculation of T-test, there are several steps to be taken, there are as follows: 1 Determine mean of variable X with formula: � 1 = ∑ � � 1 2 Determine mean of variable Y with formula: � 2 = ∑ � � 2 3 Determine Standard deviation variable X with formula: SD 1 = � ∑� 2 � 4 Determine Standard deviation of variable Y with formula: SD 2 = � ∑ � 2 � 5 Determine Standard error of variable X with formula: SE M 1 = �� 1 √�−1 6 Determine standard error of variable Y with formula: SE M 2 = �� 2 √�−1 7 Sudjiono, Anas. Pengantar Statistik Pendidikan., Jakarta: Rajawali Pers, 2010. p.240 7 Determine standard error means of differences mean of variable X and variable Y, with formula: SE M1-M2 = ��� �1 2 + �� �2 2 8 Determining t with formula: t ₒ = M ₁ − M₂ SE м 1 − м 2 9 Determining t-table in significance level 5 with Degree of Freedom df: df = N1+N2 – 2 6 The Statistical Hypotheses A hypothesis is a tentative statement about the relationship between two or more variables. This research is designed to find out whether there is a significant progress of cooperative learning specifically using songs in teaching vocabulary. In order to get the answer of that hypothesis, the writer proposed Alternative Hypothesis H a and the Null Hypothesis H which is described to the following statistical hypothesis: a If t test t t- table t t in significant degree of 0,05, the alternative hypothesis H a is accepted and the null hypothesis H is rejected b If t test t t- table t t in significant degree of 0,05, the alternative hypothesis H a is rejected and the null hypothesis H is accepted. Meanwhile, the degree of freedom df = N1+N2-2 = 20+20-2 = 38. It must be calculated with t-table of df. If df is 38, the value of significance level 5 is 1,686. 27

CHAPTER IV RESEARCH FINDINGS

This chapter describes research findings containing the description of data, data analysis, and interpretation of the data.

A. Data Description

In the data description, the writer described the data which had been collected from students’ pre-test and post-test scores of vocabulary. The pre-test was given before treatment to the experimental class and the controlled class. The post-test was given after the treatment was conducted. It was given into the experimental class by playing the song to the students while the post-test for the controlled class was by using conventional method. Here are the table descriptions of pre-test and post-test scores: Table 4.1 The Students’ Pre-test and Post test Score in Class VIII-6 The Experimental Class Number Students’ Pre-test Post-test X1 X2 1 S1 45 65 2 S2 50 65 3 S3 45 65 4 S4 45 60 5 S5 55 60 6 S6 50 70 7 S7 55 70 8 S8 60 75 9 S9 45 70 10 S10 55 75 11 S11 65 75 12 S12 55 75 13 S13 65 80 14 S14 65 80 15 S15 70 85 16 S16 70 85 17 S17 60 80 18 S18 70 85 19 S19 75 85 20 S20 60 80 Amount 20 1160 1485 Mean 58 74.25 Based on the table above it is showed that the score of the experimental class between pre-test and post-test were different. The mean of students’ score in the pre-test is 58 with the lowest score of pre-test is 45 and the highest score of pre-test is 70. Meanwhile, the mean of the students’ score in the post-test is 74.25 with the lowest score of post-test is 60 and the highest score of post-test is 85. Here is table of the frequency distribution of pre-test and post-test of controlled class. Table 4.2 The Students’ Pre-test and Post -test Score in Class VIII-2 The Controlled Class Number Students’ Pre-test Post-test Y1 Y2 1 S1 45 55 2 S2 45 60 3 S3 45 55 4 S4 50 60 5 S5 50 55 6 S6 55 65 7 S7 55 60 8 S8 55 65 9 S9 60 70 10 S10 60 70 11 S11 60 65 12 S12 65 70 13 S13 65 75 14 S14 65 65 15 S15 65 70 16 S16 65 75 17 S17 70 80 18 S18 70 75 19 S19 70 80 20 S20 70 75 Amount 20 1185 1345 Mean 59.25 67.25 Based on the table above it is showed that the score of the control class between pre-test and post-test were different. The mean of students’ score in the pre-test is 59.25 with the lowest score of pre-test is 45 and the highest score of pre-test is 70. Meanwhile, the mean of the students’ score in the post-test is 67.25 with the lowest score of post-test is 55 and the highest score of post-test is 80.

1. Pre-test score

The writer has calculated the result of pre-test in both of the two classes and the description of pre-test scores of experiment class and controlled class will be explained in table 4.3.