Test of Significance Difference of Average Scores Mean between the

52 1812.95 – 2176.2 t = 2209 + 4914 1 + 1 20 + 20 – 2 20 20 t = + 7.25 2173 2 38 20 t = +7.25 1.87631578947368 t = +7.25 1.369786768 t = 5.293

4.3 Test of Significance

To examine whether the difference between the means of the control and experimental group id statistically significant, the t-value obtained should be consulted with the critical value in the t-table. I used the 5 0.05 level of significance. The number of subjects from both groups was 40, so the degree of freedom was 38, which was obtained from the formula: Σ Nx + Σ Ny - 2. For five percent alpha level and 38 Degree freedom. The t-table was 2.42 The obtained t-value was 5.293 so the t-value was higher than the critical value. Since the obtained t-value was higher 53 than the critical value on table 5.293 2.42 the difference was statistically significant. Therefore, based on the computation there was significant difference between teaching vocabulary after and before adding a game. It could be seen by the result of the test where the students’ score was higher after the treatment.

4.4 Difference of Average Scores Mean between the

Experimental and the Control Class The experimental class and the control one were used to play a flash game in computer laboratory as media to teach vocabulary was more effective than expository one. Considering the result of the test gained by two classes, we can see which class got better achievement. The average of the control group on Pre-Test Mc = Σ Xc Nc Mc = 1308 20 Mc = 65.4 The average of the control group on Post-test Mc = Σ Xc Nc Mc = 1397 20 Mc = 69.85 The rise of the average scores: 54 69.85 - 65.4 = 4.45 For the control group, the average after the treatment increased only 4.45 point. The average of the experimental group on Pre-Test M E = Σ X E N E M E = 1376 20 M E = 68.8 The average of the experimental group on Post-Test M E = Σ X E N E M E = 1610 20 M E = 80.5 The rise of the average score: 80.5 - 68.8 = 11.7 For the experimental group, the average after the treatment increased 11.7 point. After looking at the different development on the average between the two classes, there was different achievement. The experimental class got better development, the average increased 11.7 point from 68.8 to 80.5 , whereas the control class only increased 4.45 from 65.4 to 69.85. 55

4.5 Discussion of Research Findings