CHAPTER III
dependent variable is the variable which researcher observes to determine the effect of the independent variable. The independent variable of this research is Compare-Diagnose-Operate strategy and the dependent variable is the writing score.
In this research, the researcher used experimental research with quantitative approach. The researcher wanted to know the influence of Compare-Diagnose-Operate (CDO) strategy towards writing ability of the second grade students at SMAN 11 Bengkulu.
B. Population and Sample 1. Population
Population is not only about the quantity of the subject/object that is going to be learnt, but also involves the whole characteristics of the subject or object.39 The research had been conducted at SMAN 11 Bengkulu. The school is located at Budi Utomo streat, Kelurahan Kandang, Bengkulu, where it was on the outskirt of the town. The location of this school was far from the main street. It made the situation of teaching and learning process run well because the situation is conducive and comfortable. Thus, in this research the population were all of the second grade students at SMAN 11 Bengkulu on second semester. The second grade of SMAN 11 Bengkulu consists of three (3) classes that were classified into two; XI IPS and XI IPA. XI IPS consists of two (2) classes, meanwhile XI IPA only one (1) class.
39 Sugiyono, Metode Penelitian Pendidikan Pendekatan Kuantitatif, Kualitatif dan R &
D. (Bandung : Alfabeta 2010) Page 89
Table 3.2
Distribution of Population
No Class Number
Male Female Total Mean Score
1 XI MIA 1 15 17 32 73,3
2 XI MIA 2 12 16 28 71,3
2 XI IPS 1 15 15 30 74,5
3 XI IPS 2 12 17 28 72,5
Total 54 65 119 291.6
Source: SMA N 11 Bengkulu (TA. 2019/2010) 2. Sample
Sample is part of population that is chosen as the representative.40 Since the design belongs to pre-experimental, the researcher used purposive sampling in determining the sample. In purposive sampling sample elements are judged to be typical and representative. The researcher must take sampling decision early in the overall planning to take sample of the research. In this case, the researcher took two classes of second grade students, first, XI IPS 2 class as the experimental class and second, XI MIA 2 as the control group. The researcher decided the two classes because the two classes have the same or almost the same capability in writing English. The influence is known after find out the significant difference between the students taught before using Compare- Diagnose-Operate (CDO) strategy and after Compare-Diagnose-Operate (CDO) strategy by comparing pre-test and post-test score.
Table 3.3
40 Sukardi, Metodologi Penelitian Pendidikan Kompetensi dan Prakteknya. Jakarta : Bumi Aksara. 2003) page 54
Sample of the Research
No Class Number
Male Female Total
1 XI IPS 2 12 17 29
2 XI MIA 2 12 16 28
C. Technique of Data Collection
In collecting the data, the researcher used test. The researcher did the pre-test and post-test for all of the samples. The pre-test was given to both control and experimental groups. The data was collected by giving the test to the students. Pre-test to find out the students ability before the students were given the treatment. In the treatment, the researcher taught the students in experimental class using Compare-Diagnose-Operate (CDO) strategy as media and control class without the treatment. Then, post-test to find out students achievement after the students treat by Compare-Diagnose-Operate strategy.
D. Research Instrument
Research instrument refers to any equipment used to collect the data.41As an experimental research, the instrument used in this research was writing test. Test is a set of stimuli presented to individual in order to elicit responses on the basis of which a numerical score can be assigned.
The test is used to find out the ability of students‟ writing persuasive text after learning by using Compare-Diagnose-Operate (CDO) strategy. The researcher asked the students to write persuasive text based on their mind.
41 Arikunto, Suharsimi, Metode Penelitian : Prosedur Penelitian Suatu Pendekatan Praktik. PT : Rineka Cipta, 2006. Page 262
The pretest and posttest was about writing persuasive text. The researcher gave the pretest and posttest to both control and experimental groups.
E. Research Procedures
The Stages for the Experimental Group
The researcher taught writing using Compare-Diagnose-Operate (CDO) Strategy where each meeting took time allocation about 2x 45 minutes.
1. Pre-activities
1) The researcher prepared the students physically and mentally for the learning process. Firstly, the researcher greeted and checked the attendance list. Then, the researcher gave the warm up activities.
2) After the students were ready to study, the researcher introduced the lesson to the students. The researcher explained the topic or wrote it down in the board. When the students are regarded understand about the topic, the researcher conveyed the lesson objective for that meeting; at the end of the class, the students were expected to be able to write a persuasive text.
2. While-activities
The researcher started using Compare-Diagnose-Operate (CDO) strategy before introducing the topic of the lesson. This strategy consisted of three steps; those were Compare, Diagnose, and Operate.
1) First, the researcher applied Compare, students wrote a persuasive text based on what was in student‟s mind. After a student answered orally, the researcher asked the student to write it down in a form of persuasive text on the board.
2) Second, the researcher applied the next step that was Diagnose ( the students checked whether there were mistakes in their persuasive text by themselves). In this case, the researcher looked at that writing and gave comment. Next, some students gave comment orally before they completed the text on the board. Some students found any mistakes on the text such as changed words, deleted or added ideas, or used of simple present tense in the text as a persuasive text should be.
3) Finally, the researcher applied the third step, that was Operate (the students revised and re-wrote their text) the researcher asked students which had written the text down on the board to improve the text and re-wrote it on a new persuasive text. The students were not allowed to delete the mistakes of previous text, but they had to write the change on a new persuasive text.
3. Post-activities
Before class is ended, the researcher evaluated the students‟ writing on the board which related to communicative purpose of the text, the use of the language features, and organization of the text. The activities done in this phase are :
a. The researcher gave a conclusion about persuasive text.
b. The researcher gave homework to the students c. At the end, the researcher closed the class.
The Stages for the Experimental Group
In the control group, the students were given pretest and posttest but received no treatment at all.42 The researcher taught the control group as well. However, the researcher taught the students by conventional strategy.
F. Technique of Analysis Data
The researcher analyzed the data in the last step of this research. In analyzing the data, the researcher used t-Test formula to the effect of the treatment, the researcher grouped the student writing ability based on the score element of content, organization, vocabulary, language use / grammar, and mechanics. Before analyzed using t-Test, to know if the data distributed normally normal or not, the researcher did the normality and homogeneity first. The researcher analyzed the data by using Statistical Package for Social Science (SPSS) 16 program. Furthermore, the researcher found out the means score and standard deviation of the pre-test and post-test to see the differences. Eventually, in comparing the means score of the test, the researcher decided whether those differences were likely to happen by chance or by treatment effect. The formula for the t- test can be seen as follow:
42 McMillan, D. An Interactive Guide to Educational Research: A Modular Approach (Boston:
Allyn and Bacon, 1992), p. 176
√(
√ ) (
√ ) Where : t0 : the value will e found
Mx : the average score of the experimental group My : the average score of the control group
SDx : Standard deviation of the experimental group SDy : Standard deviation of the control group N : the number of students
CHAPTER IV
RESULT AND DISCUSSION A. RESULTS
In this chapter, the result and discussion of the research were presented. The result showed that the implementation of using Compare- Diagnose-Operate (CDO) strategy at second grade students of SMAN 11 Bengkulu was increased. The findings also included the result of the study that showed whether there was significant differences of students‟ writing persuasive text between the experimental class and control class who were taught using Compare-Diagnose-Operate (CDO) strategy and those who were not. The result of the research were obtained based on the data analysis.
1. The Result of Writing Persuasive Text
This section described and analyzed the test before and after the pre-test, the treatment, then the post-test were given to the students in the experimental group and the control group.
1.1 The Description of Pre-test Score and Post-test Score in the Experimental Group
The score of students‟ pre-test and the-post test of in the experimental group can be seen on table 4.1
Table 4.1
The Score Distribution of Experimental Group Score
Interval Category Pre-test Post-Test
Frequency Percentage Frequency Percentage 80-100
70-79 60-69 50-59
<49
Excellent Good Average
Poor Very poor
0 9 15
3 2
0 31 % 51.7 % 10.3 % 6.8 %
2 20
6 1 0
6.8 % 68.9 % 20.6 % 3.4 %
0
Based on the table above, the pre-test in the experimental class, there was none student on excellent category, 9 (31%) students on good category, 15 (51.7 %) students on average category, 3 (10.3%) students on poor category, and 2 (6.8 %) students on very poor category. While in post-test, there was 2 (6.8 %) students were on excellent category, 20 (68.9
%) students were on good category, 6 (20.6%) students were on average category, 1(3.4%) students was on poor category, and 0 (0%) student was on very poor category.
Graphically, the total score of students pre-test and post-test in the experimental group can be seen on figure 4.1
Figure 4.1
Graph for Pre-test and Post-test score of experimental group
Based on figure 4.1 , the post test score was higher than the pretest scores. It means teaching writing recount text by using Compare- Diagnose-Operate (CDO) strategy increased the students writing persuasive text.
1.2 The Description of Pre-test Score and Post-test Score in the Control Group
The score of students‟ pre-test and the-post test of in the experimental group can be seen on table 4.2
0 5 10 15 20 25
Excellent Good Average Poor Very Poor
Pre-Test Post-Test
Table 4.2
The Score Distribution of Control Group Score
Interval Category Pre-test Post-Test
Frequency Percentage Frequency Percentage 80-100
70-79 60-69 50-59
<49
Excellent Good Average Poor Very poor
0 8 15
3 1
0 % 28.5 % 53.5 % 10.7 % 3.5 %
0 15 12 1 0
0 % 53.5 % 42.8 % 3.5 %
0
Based on the table above, the pre-test in the control class, there was none student on excellent category, 8 (28.5%) students on good category, 15 (53.5 %) students on average category, 3 (10.7%) students on poor category, and 1 (3.5 %) student on very poor category. While in post-test, there was 0 (0 %) student was on excellent category, 15 (53.5 %) students were on good category, 12 (42.8 %) students were on average category, 1(3.5%) students was on poor category, and 0 (0%) student was on very poor category.
Graphically, the total score of students pre-test and post-test in the experimental group can be seen on figure 4.2
Figure 4.2
Graps for pre-test and post-test in Control Group
Based on figure 4.2 , it was showed that the post-test and pre-test score were relative the same. The highest frequency on pre-test was on average category. Meanwhile, the highest frequency on post-test was on good category. It meant the score of the students‟ writing persuasive text increased gradually.
2. The Normality and Homogeneity of the Data
Homogeneity and normality of the data should be measured before analyzing the data. Test normality is used to find out whether the score distributed normally or not. If the significance > 0,05, it means the test distribute normally. If the significance < 0,05, it means the test is not distribute normally. The Kolmogorov smirnov test was used to measure the data because the data of each group less than 50 data.
0 2 4 6 8 10 12 14 16
Excellent Good Average Poor Very Poor
Pre-test frequency Post-test frequency
2.1 The Result of Normality Data Test of Pre-Test Scores Table 4. 3
Test of Normality of Pre-Test Scores in the Experimental Group
One-Sample Kolmogorov-Smirnov Test
pretest
N 29
Normal Parametersa Mean 65.62
Std. Deviation 7.775
Most Extreme Differences Absolute .142
Positive .072
Negative -.142
Kolmogorov-Smirnov Z .762
Asymp. Sig. (2-tailed) .606
a. Test distribution is Normal.
Based on the data above, the Kormogorov-Smirnov test of the pre- test in the experimental class showed that the significance was 0.606. It was higher than 0.05. It meant that the data obtained were considered normal.
The histogram of the normal data of pre-test score of experimental class can be seen on the figure below :
Figure 4.3
The Histogram of the Students’ Pre-test of the Experimental Class
Table 4.4
The Normality Pre-Test Scores of the Control Group
One-Sample Kolmogorov-Smirnov Test
Pre-test
N 28
Normal Parametersa Mean 65.11
Std. Deviation 6.332
Most Extreme Differences Absolute .098
Positive .078
Negative -.098
Kolmogorov-Smirnov Z .516
Asymp. Sig. (2-tailed) .953
One-Sample Kolmogorov-Smirnov Test
Pre-test
N 28
Normal Parametersa Mean 65.11
Std. Deviation 6.332
Most Extreme Differences Absolute .098
Positive .078
Negative -.098
Kolmogorov-Smirnov Z .516
Asymp. Sig. (2-tailed) .953
a. Test distribution is Normal.
The Kormogorov-Smirnov test of the pre-test in the control class showed that the significance was 0.953. Since 0.953 > 0.05, it concluded that the data obtained were considered normal.
The histogram of the normal data of pre-test score the control group can be seen on figure :
Figure 4.4
The Histogram of the Students’ Pre-test of the Control Class
2.2 The Result of Normality Data Test of Post-Test Score Tabel 4.5
Test Normality of Post-Test Scores Experimental Group
One-Sample Kolmogorov-Smirnov Test
Post-Test
N 29
Normal Parametersa Mean 73.21
Std. Deviation 6.270
Most Extreme Differences Absolute .182
Positive .109
Negative -.182
Kolmogorov-Smirnov Z .982
Asymp. Sig. (2-tailed) .290
One-Sample Kolmogorov-Smirnov Test
Post-Test
N 29
Normal Parametersa Mean 73.21
Std. Deviation 6.270
Most Extreme Differences Absolute .182
Positive .109
Negative -.182
Kolmogorov-Smirnov Z .982
Asymp. Sig. (2-tailed) .290
a. Test distribution is Normal.
The The Kormogorov-Smirnov test of the post-test in the experimental group showed that the significance was 0.290. Since 0.290 >
0.05, it concluded that the data obtained were considered normal.
The histogram of the normal data of post-test scores of the experimental group can be seen on figure :
Figure 4.5
The Histogram of the Students’ Post-test of the Experimental Group
Tabel 4.6
Test Normality of Post-Test Scores of Control Group
One-Sample Kolmogorov-Smirnov Test
Post-Test
N 28
Normal Parametersa Mean 70.21
Std. Deviation 5.921
Most Extreme Differences Absolute .148
Positive .119
Negative -.148
Kolmogorov-Smirnov Z .781
Asymp. Sig. (2-tailed) .575
a. Test distribution is Normal.
One-Sample Kolmogorov-Smirnov Test
Post-Test
N 28
Normal Parametersa Mean 70.21
Std. Deviation 5.921
Most Extreme Differences Absolute .148
Positive .119
Negative -.148
Kolmogorov-Smirnov Z .781
Asymp. Sig. (2-tailed) .575
The The Kormogorov-Smirnov test of the post-test in the experimental group showed that the significance was 0.575. Since 0.575 >
0.05, it concluded that the data obtained were considered normal.
The histogram of the normal data of post-test scores of the experimental group can be seen on figure :
Figure 4.6
The Histogram of the Students’ Post-test of the Control Group
2.3 The Result of Homogeneity of Variances Test
The result of homogeneity of variances test can be seen on table 4.7 Table 4.7
Test of Homogeneity of Variances
Test of Homogeneity of Variances
Score
Levene Statistic df1 df2 Sig.
.074 1 55 .787
The test homogeneity of variences showed that the significant were 0.787. Since 0.787 was higher than alpha level of 0.05, it concluded that the variances of every test were homogenous.
3. The Statistical Analysis Result
To verify the hypothesis proposal, the researcher applied the statistical analysis. The tests are T-test and independent sample t-test. T-test which is paired t-test was used to find out whether there were significant differences in students‟ writing persuasive text before and after the treatment in both experimental and control group, meanwhile independent sample t-test was used to find out whether there was significant differences between experimental group and control group. The researcher used Statistical Package for Social Science (SPSS) 16 program for windows in order to find the paired sample t-test and independent sample t-test.
3.1. Paired Sample T-Test Analysis
Statistical Analysis on the Result of Pre-test and Post-test in the Experimental Group
Table 4.8
Paired Samples Statistics
Mean N Std. Deviation Std. Error Mean
Pair 1 PRETEST 65.6207 29 7.77548 1.44387
POSTTEST 73.2069 29 6.26999 1.16431
Based on the table above, the mean of writing pre-test of the experimental group was 65.62 and the standard deviation was 7.775. Meanwhile, the mean of post-test in the experimental group was 73.20 and the standard deviation was 6.269.
From the table above, the result of paired sample difference in mean between pre-test and post-test of writing in the experimental group was 7.58 with standard deviation 6.17 at the significant level of 0.05 and degree off freedom (df) 28 and the value of t-table for two tailed test was 0.000.
Thus, it could be seen that t-obtained significant two tailed , 0.000
< 0.05. It means that the researcher hypothesis (Ha) was accepted and the null hypothesis (Ho) was rejected. It means that there was significance influence in experimental group.
Statistical Analysis on the the Result of Pre-test and Post-test in the Control Group
Table 4.10
Paired Samples Statistics
Mean N Std. Deviation Std. Error Mean
Pair 1 PRETEST 65.1071 28 6.33239 1.19671
POSTTEST 70.2143 28 5.92144 1.11905
Paired Differences
t df
Sig. (2- tailed)
Mean
Std.
Deviation
Std. Error Mean
95% Confidence Interval of the Difference
Lower Upper
P a i r
1
PRETEST – POSTTEST
-
7.58621 6.17898 1.14741 -9.93657 -5.23585 -
6.612 28 .000
The result of paired samples statistic above, the mean of pre-test in the control group was 65.107 and the standard deviation was 6.332. Meanwhile, in post-test the result of mean was 70.21 and the standard deviation was 5.921.
Table 4.11
Paired Samples Test of Control Group
Paired Differences
T df
Sig. (2- tailed) Mean
Std.
Deviation
Std. Error Mean
95% Confidence Interval of the
Difference Lower Upper Pair
1
PRETEST -
POSTTEST -5.10714 6.00209 1.13429 - 7.4345 1
-2.77977 -4.503 27 .000
The result of the paired sample t-test, paired sample difference in mean between pre-test and post-test of writing skills in the control group was -5.107 with standard deviation was 6.002 and t-obtained -4.503 at the significance level of 0.05 and the degree of freedom 27 and the value of t- table two tailed test was 0.000.
Thus, it could be seen that significance two-tailed was 0.000 was lower than the 0.05. It meant that the researcher hypothesis (Ha) was accepted and the null hypothesis (Ho) was rejected. It means that there was significance influence in control group.
3.2. Independent Sample T-test Analysis of Students’ Writing Persuasive Text
Table 4.12
Independent Samples Test
Levene's Test for Equality of
Variances t-test for Equality of Means
F Sig. T Df
Sig.
(2- tailed)
Mean Difference
Std. Error Difference
95% Confidence Interval of the
Difference Lower Upper Result Equal
variances assumes
.007 .932 2.178 55 .034 3.45690 1.58728 .27592 6.63787
Equal variances not assumes
2.182 54.791 .033 3.45690 1.58452 .28117 6.63262
The independent sample showed the comparison of post-test of experimental group and control group displayed the difference between both scores. It was identified that t count 2.178. From the data, it was concluded that alternative hypothesis (Ha) was accepted and null hypothesis (Ho) was rejected. It mean that was significant influence in writing skills of persuasive text scores between the students who were taught by using Compare- Diagnose-Operate (CDO) strategy and those who were not.
B. DISCUSSION
Experimental and control group were same in their initial level of writing skills as indicated by the writing pre-test were given before the treatment. The mean score of pre-test in experimental group was 65.62 and the mean score of control group was 65.10. Statistical analyzing has revealed that