asymp.sig 0.05, the null hypothesis is not rejected and alternative hypothesis is rejected. It declares that there is no difference of means
between experimental and control group.
2. Effect Size
The effect size computation is conducted to check the level of effect of treatment after the t-test calculation by using SPSS 20.0 from independent t-
test of post-test. It was used to determine the significance impact of the
treatment of the experimental group. The formula is:
√
The t refers to the t value obtained from the independent t-test calculation on post-test data. Afterward, the df is the amount of samples minus by 2 df-
N-2. After obtaining the r value, in addition, it is analyzed by using effect size scale
4
.
Table 3.2 The Scale of Effect Size
Effect size r value
Small 0.100
Medium 0.243
Large 0.371
H. Statistical Hypothesis
4
Ibid., p. 106
According to Hatch and Farhady, hypothesis means a tentative statement about the outcomes of the research, it indicates that question must answered
by doing experiment
5
. Two hypothesis are formulated as follows:
H : µ
1
= µ
2
, or H
A
: µ
1
≠ µ
2
Specifically, the hypothesis in this study is the form of the null hypothesis and alternative hypothesis. The null hypothesis H
indicates there is no significant difference in means between control and experimental group.
Meanwhile, the alternative hypothesis H
A
means that there us a significant difference between control and experimental group.
5
Hatch and Farhady, Research Design and Statistic for applied linguistics, Los Angeles: Newbury House Publishers, Inc, 1982 p. 86.
22
CHAPTER IV FINDINGS AND DISCUSSION
This chapter discusses two points. First, it presents the data gathered. Second, the data collected are analyzed concerning the research questions stated in this paper
and elaborated based on theories established.
A. Findings 1. Pilot test Result
As stated in chapter III, the pilot test went through two steps. Firstly, the instrument was validated by an English teacher. Secondly, the instrument
was administered to five students who did not included in both control and experimental groups in academic year 20132014. The result of the pilot test
is shown in the following table.
Table 4.1 The Result of Pilot Test
Aspect Student no. 1
Student no. 2 Student no. 3
Student no. 4 Student no. 5
Assessors’
Assessors 1
Assessors 2
Assessors 1
Assessors 2
Assessors 1
Assessors 2
Assessors 1
Assessors 2
Assessors 1
Assessors 2
Content 2
3 2
3 3
3 1
3 1
2 Vocabulary
2 3
3 3
2 3
2 3
2 3
Generic Structure
2 3
3 3
2 3
2 3
2 3
Language Feature
2 3
2 3
2 3
2 3
1 3
The Students are able to develop the argumentative writing based on the given topic that familiar for them. It can be seen from the scores that the
students got. As mentioned before, this research adopts the rubric of Brown. From the aspects, if the students get three scores mean that the contents that
the students write are understanable, two scores mean that there are many
confused word. For example; the writing is irrelevant with the topic, and one score means that so many mistakes.
Most of the students get the score between 1 until 3. For example, in vocabulary aspect, one student get three scores means that the words have
already been related to the topic and situation; however, they are not have any variation yet. Four students get two scores which mean that there are still lots
of unappropriate word used in the students write. From the table it can be seen that although the score is not high enough, the students can write and
understand what the instruction gives.
2. Pretest Result
Pre-test was conducted on August 13
st
, 2014 to 25 students in class XI A and 25 students in class XI B 20142015. Students’ writing in pre-test
was evaluated based on the rubric of Brown which covers content, vocabulary, generic structure, and language features. Later, the scores were
statistically analyzed by using SPSS 20.0 for windows by following several steps.
Normal Distribution Test
The normality test was employed by using Kolmogorov-Smirnov test to know whether or not the score of the students were normally distributed.
Before examining the normality of the scores, the hypotheses null and an alternative hypothesis were established. The result of the analysis is
presented in the following table.
Table 4.2 Tests of Normality
Kolmogorov-Smirnov Shapiro-Wilk
Statistic df
Sig. Statistic
df Sig.
EXPERIMENTAL GROUP CONTROL GROUP
.148 .119
25 25
.162 .200
.949 .949
25 25
.239 .234
