46
7.51 to 8.46 or the scores of the control group from pre-test to post-test are more heterogeneous. It can be concluded that the scores of the experimental group
become homogenous while the scores of the control group become heterogeneous.
4.2 Data Analysis
To find out there is a significance different or not which happens to the student’s mastery of speaking between the students’ who were taught using
discussions technique and those who were not taught using discussion technique , the t-test was applied. Before the t-test was operated, the pre analysis testing was
applied in this research. The pre analysis testing included test of normality and test of homogeneity. The discussion of the pre analysis testing is as follows.
4.2.1 Test of Normality The normality test is used to know whether the distribution of scores is
normal or not. In this case, the chi – square technique is employed. The
distribution is said to be normal if obtained Chi-square value x
o 2
is lower than the critical value x
t 2
with the significance level of 5 and dƒ equals with n –1.
The following table confirms the summary of the normality test result.
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Table 13. Result of the Test of Normality
Variable
x
o 2
x
t
5
D
ƒ P
Statement Test
Experimental Group KA
8.839 28.863
18 0.963
Normal Pre-test
Experimental Group KA
13.742 28.863
18 0.746
Normal Post-test
Control Group TPA
12.625 26.296
16 0.700
Normal Pre-test
Control Group TPA
14.000 33.924
22 0.901
Normal Post-test
x
o 2
= The Chi-square of the observation.
x
t
5 = The Chi-square of the table in the significance level of 5. D
ƒ =
Degree of freedom.
p
= Degree of significance p 0.05 = normal. In the pre-test, table 14 above shows that x
o 2
value of the pre-test of two groups the experimental and control groups is lower than x
t
5 value, which are 8.839 28.863 and 12.625 26.269. Thus, it can be stated that the data tend to be
normal. The level of significance of the groups is also higher than 0.05, which are 0.963 0.05 and 0.700 0.05. Therefore, the pre-test data of the groups is once
again, proved to be normal. In the post-test, the table 14 above shows that x
o 2
value of the post-test of two groups the experimental and control groups is lower than x
t
5 value, which are 13.742 28.863 and 14.000 33.924 so, it is clear that the data is
normal. The level of significance of the groups is also higher than 0.05, which are 0.746 0.05 and 0.901 0.05 .Once again, the post-test data of the groups are
proved to be normal. The print out of the analysis is in Appendix.
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4.2.2 Test of Homogeneity The homogeneity test is applied to know whether the two groups are in the
same condition or whether the sample variance is homogeneous or not. The analysis technique employed to analyze whether the sample variance is
homogeneous or not is the F-test. The table below describes the descriptive analysis of the homogeneity test result.
Table 14. Descriptive Analysis of the Homogeneity Test Result
ANOVA Sum of
Squares D
ƒ Mean
Square Fo
�
�
5 p
Between Groups
780.567 16
48.785 .
0.706 2.46
0.750 Within
Groups 966.917
14 69.065
Total 1747.484
30
F
�
= F value on the observation. F
�
5 = F value of the table in the significance level of 5.
df = Degree of freedom
MST = Mean Square TreatmentBetween Group
MSE = Mean Square TreatmentWithin Group
p
= Degree of significance p 0.05 = normal.
It can be seen from the table that the value of Fo is less than Ft, which is 0.706 2.46
the complete computation is enclosed in Appendix. So, it can be declared that the sample of variance is homogeneous. The level of significance is more
than 0.05, which is. 0.750 0.05. Therefore, the sample of variance is, once again confirmed to be homogeneous.
49
4.2.3 Inferential statisticHypothesis Testing `
The test of hypothesis aims at revealing whether there is a significant difference between the two groups in their mean scores of the English speaking
mastery test or not . The hypothesis of this research is “There is a significant
difference in the English speaking skill mastery between the students who are taught using discussion technique and those who are taught without using
discussion technique ”.
Table 15 . Gain Score of the Students’ Speaking Mastery
Variable N Pre-Test
Post-Test Gain
Mean SD
Mean2 SD2
Mean3 SD3
KA 31
58.87 7.63
80.64 7.43
21.77 6.60
TPA 32
59.60 7.51
70.65 8.46
11.05 5.28
N = the number of the students
SD = standard deviation
The table above shows that the mean of the post-test scores of the experimental
group is higher than that of the control group, which is 80.64 70.65. Then, the mean score of the gain scores of the experimental group is also higher than that of
the control group, which is 21.7711.05. It confirms that the use of discussion technique is effective to improve students’ speaking mastery.
Moreover, the standard deviation of the experimental group decreases from 7.63 to 7.51 or it is more homogenous. While, the standard deviation of the
control group increases from 7.51 to 8.46 or it is more heterogeneous. It can be concluded that the scores of the experimental group become homogenous while
the scores of the control group become heterogeneous.
50
Table 21
illustrates the summary of the t- test analysis result of the students’ speaking mastery.
Table 16. T-test Result of the Pre-Test
Variable �
�
�
�
5 D
ƒ Р
Conclusion KA-TPA
-0.24 1.697
30 0.811
�
�
�
�
KA = The experimental group
TPA = The control group �
�
= t value on the observation dƒ
= Degree of freedom n – 2
�
�
5 = t value of the table in the significance level of 5.
p
= Degree of significance p 0.05 = normal. The table indicates that
�
�
is lower than the t value at the significance level of 5, which is. -0.24 1.697. The significance level is 0.811. It is higher than 0.05.
Therefore, it can be stated that the pre-test scores of the experimental group is not significantly different from that of the control group. It means that in the
beginning , the student’s mastery of the pre-test between students who are taught
with discussion technique in the English teaching and learning process and those who are not taught with discussion technique in the English teaching and learning
process is not significantly different.
Table 17. T-test Result of the Post-Test
Variable �
�
�
�
5 D
ƒ Р
Conclusion KA-TPA
4.219 1.697
30 0.00
�
�
�
�
The table indicates that �
�
is higher than the t value at the significance level of 5, which is. 4.219 1.697. The significance level is 0.00. It is lower than 0.05.
Therefore, it can be stated that the post-test scores of the experimental group is significantly different from that of the control group. It means that in the end, the
51
students’ speaking ability of the post-test between students who are taught with discussion technique in the English teaching and learning process and those who
are not taught with discussion technique in the English teaching and learning
process is significantly different.
Table 18. T-test Result of the Gain
Variable �
�
�
�
5 D
ƒ Р
Conclusion KA- TPA
6.103 1.697
30 0.00
�
�
�
�
The table indicates that �
�
is higher than the t value at the significance level of 5, which is. 6.103 1.697. The significance level is 0.00 It is lower than 0.05.
Thus, the null hypothesis of no treatment effect is rejected and the proposed hypothesis which states “There is a significant difference in the student’s mastery
of speaking between the students who are taught using discussions technique and those who are taught without using discussion technique
” is accepted.
4.3 Interpretation of the Findings
