Homogeneity Test Pre- Testing Analysis

experimental class was 24.21. In brief, it seems that the improvement of the mean score in experimental class was higher than that of the control class. The improvement of the mean score of writing test of the control and experimental classes is presented in Table 23. Table 23: The Improvement of the Mean Score of Writing Tests of the Control and Experimental Classes Variable Mean The Impovement Control Class Pre-test 58.10 7.99 Post-test 66.09 Experimental Class Pre-test 57.89 24.21 Post-test 82.10 Based on the result Table 23, it indicated that the students of the control and experimental classes had the same writing ability before the treatment given. It could be seen from the score categorization of the pre-test scores in both classes. It indicated that the students’ pre-test scores in the both classes tended to be classified into the fair category. Then, after the control and experimental classes were given a different treatment, the improvement of the mean in the experimental class was higher than the control class. It could also be seen from table of scores categorization of both classes that the post-test scores of the experimental class were classified into very good category while the post-test scores of the control class were classified into the good category. The inferential analysis result indicated that all of the data had normal distribution and the ample variances were homogeneous. It could also be seen from the result of the normality test of the both classes that the probability value of the pre-test data of the control and the experimental group was higher than 0.05,i.e.0.180 0.05 and 0.743 0.05. So, the pre-test data of the groups had normal distribution. Meanwhile, the probability values of the post-test data of the control and experimental classes were also higher than 0.05, i.e.0.330 0.05 and 0.558 0.05. So, the post-test data of the both classes were also normal. It was concluded that all of the data had normal distribution. Meanwhile the result of the homogeneity testing also indicated that the p value was greater than the significance level of 0.05 for the both pre- and post- tests,i.e.,0.155 0.05 and 0,562 0.05. So, it was stated that the sample variance in the pre- and post- tests were homogeneous. Then, from the ANCOVA result, it can be seen that the value of the level of significance is lower than 0.05, i.e. 0.00 0.05, which means that there is a significance difference in the post-test score between the two groups after controlling the pre-test scores as the covariate. Besides, the significant difference also can be seen from the adjusted means of both classes as presented in Table 24. Table 24: Summary Means Variable N Post-test Adjusted Mean Experimental Class 32 82.10 81.17 Control Class 32 66.09 64.77 Table 24 shows that the mean score of the post-test achieved by the experimental class taught using inquiry based-learning strategy is higher than the mean score of the control class i.e. 82.1066.9. Then, because the means of the covariate or the pre-test were not exactly the same for the two classes, the means of the dependent variable or the post-test had to be adjusted. The adjusted mean of the experimental class is also higher than that of the control class i.e. 81.17