Furthermore, after obtaining the result of Independent-Sample T Test
in both the the experimental and the control class’ pretest which proved that both of the classes had no extreme difference in narrative
writing skill before the treatment was performed, the last step is to test the hypothesis. The following was the result of the experimental and the
control class’ posttest based on the Independent Sample T Test calculation:
Table 4.9 The Mean, the Standard Deviation, and Standard Error Mean of the Experimental and Control Class’ Posttest Score
Group Statistics
Class N
Mean Std. Deviation
Std. Error Mean Posttest Score Experimental
26 60.865
14.5248 2.8486
Control 26
51.827 11.9699
2.3475
The table 4.9 above showed that the mean score of posttest in the experiment class was 60.87 whereas in the control one was 51.83. It
indicated that the mean score of the experimental class’ posttest was
higher than the control one after the treatment was given.
Table 4.10 The Result of Independent Sample t-Test of the Experimental and Control Posttest
Independent Samples Test
Levenes 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
Posttest Score
Equal variances
assumed .914
.344
2.449 50
.018
9.0385 3.6912
1.6245 16.4525
Equal variances
not assumed
2.449 48.239
.018 9.0385
3.6912 1.6177
16.4592
In a similar way, to interpret the table 4.10 above, it had to see the column Equal variances assumed first in interpreting the result of
Independent Sample T test which was presented in Table 4.10 above. It
was obtained that significance level or probability value of F 0.344 was bigger than significance degree α = 0.05. It meant that variance of data
in both experimental and control class was homogenous. Because of obtaining homogenous variance data, it had to use t value t = 2.449 and df
= 50. Based on the result of Independent-Sample T Test above, it was
gained from the calculation that t
count
is 2.449 whereas t
table 0.025
is 2.009 gained based on df = 50 and
⁄ α
= 0.025 . Because of obtaining Sig. 2-
tailed from the result of Independent-Sample T Test, the degree of significance α = 0.05 had to be divided by 2. It meant that t
count
2.449 was higher than t
table
. Moreover, the value of Sig. 2-tailed was 0.018. The value meant that the significance level 0.018 or probability value p
was lower than the degree of significance
⁄
α = 0.025. The result of Independent-Sample T Test on posttest p = 0.018 was acceptable since it
could be a proof to reject the null hypothesis. Actually, the researcher concluded that the result of Independent-
Sample T Test on posttest p = 0.018 explianed above was able to reject the null hypothesis because to take the decision of the independent sample
t test for testing hypothesis, the researcher had formulated the criteria of hypothesis testing at first. The criteria of hypothesis testing mentioned that
there was no positive effect of using picture books in students’
performance in writing narrative text if t
count
t
table
or Sig 2-tailed
⁄
α. Meanwhile, if Sig 2-tailed
⁄
α or t
count
t
table,
the result could be assumed that there wa
s positive effect of using picture books in students’ performance in writing narrative text. As the criteria of hypothesis testing
mentioned above, the result of the Independent Sample T Test proved that there were scientifically significant difference in the students
’ performance in writing narrative text after using picture books as a model
for their own writing. In addition, after gaining the result of Independent Sample T Test
which proved that there was a positive effect of picture books in students’ writing narrative text, however this result could not give the answer about
how large the effect was. To determine whether the effect size is strong or not, the researcher
used Cohen’s d the 2-tailed effect size. After calculating Cohen’s d to know the effect size of picture books
treatment, the result gained from Cohen’s d was 0.68. The researcher calculated the effect size Cohen’s d using Statistics Calculators The
Effect Size Cohen’s d Calculator for a Student t-Test. The effect size
range of Cohen’s d showed that 0.50 was on category medium effect.
Additionally, the effect size range of Cohen’s d was provided in table 3.1
which was presented in CHAPTER III. Thus, the result of Cohen’s d
could be assumed that the effect size of using picture books in students’
performance in writing narrative text was moderate.
B. Discussions
Based on the test of equality of two average post-test was known that the students’ performance on writing narrative text in both the experimental and
control class showed differences. The mean score of the experimental class’
posttest which was higher 60.87 than the control class’ posttest which had the
mean score 51.83. The result of hypothesis testing using t-test obtained t
count
t
table
, namely t
count
value is 2.449, t
table
value at significance degree
⁄
α = 0.025 and df = 50 is 2.009. Thus, this result could be concluded that there was influence
of teaching narrative writing through picture books in students’ performance in
writing narrative text. Moreover, the effect size Cohen’s d of the treatment
using picture books in st udents’ narrative writing skill was 0.68. The result was
on category medium effect based on the effect size range of Cohen’s d. This result
medium effect proved that the effect size of using picture books in students’
narrative writing skill was neither weak nor strong too. So, this treatment can be applied in narrative writing instruction.
Furthermore, the summary Table 4.9 proved that the mean score in both of the experimental
and control class’ posttest improved after writing instruction was given. The mean score in the experimental class while pre-test was 40.48 and
it changed to be 60.87 in post-test. This means that the mean score in the experim
ental class’ posttest increased 20.4 after the treatment using picture books in narrative writing instruction was done. For the control class, the mean
score in pre-test was 43.56 and it changed to be 51.83 in post-test. The mean score in the control class’ posttest also increased 8.27 after the narrative writing
instruction without using picture books was conducted. However, the mean score in the experimental class’ posttest showed significant improvement compared to
the control one. Based on the summary presented in Table 4.9 above, the experimental class
had the higher mean score of posttest than the control one because during writing instruction, the experimental class was given the treatment eight picture books as
a narrative writing model which could help them to generate their ideas in creating their own story and learn the moral value of stories in picture books after
they finished reading and discussing the picture books. The finding related to Terry Miller’s theory of using picture books in all subject areas. As Terry Miller
asserts, the combination of beautifully vivid illustration and expressive language presented by picture boooks can be choosed as a stimulating prompt for students
to create their own narrative writing imaginatively.
1
This meant that the unique characters, vivid setting, and interesting plot line in picture books serve models
for students to follow up the story to develop their own narrative writing. Similarly, these findings were related to the previous relevant study
conducted by Kelly Booker, Literacy and Numeracy Field Officer, ACT entitled “Using Picture Books to Empower and Inspire Readers and Writers in the Upper
Primary Classroom”. The research conducted by Kelly Booker also found that
picture books led the students to read, explore, and connect the stories in picture books to their own experiences or interests which could help them to generate and
develop ideas in their own writing.
2
On the other hand, this previous research applied reading aloud of a variety of picture books to persuade the students to
love reading and it gave them the experiences and impressions to develop their own writing. As a matter of fact, the reading aloud could not be performed in this
research due to the great number of students in each classroom The eighth grade students of SMP PGRI Ciputat which reached to 30 students.
To sum up, based on the explanations above, the experimental class had higher improvement in
posttest’ mean score after the treatment was given than the control one. Therefore, it could be proved that there was a positive effect of using
picture books in students’ performance in writing narrative text and the effect size of using
picture books in students’ performance in writing narrative text was moderate which indicated that the effect size of the treatment was neither weak
nor strong too.
1
Terry Miller, The Place of Picture Books in Middle-Level Classrooms: Journal of Adolescent and Adult Literacy, Vol. 41, No.5, 1998, p. 379
2
Kelly Booker, Using Picture books to Empower and Inspire Readers and Writers in the Upper Primary Classroom: Literacy Learning the Middle Years, 2, 2012, p. 1-7
54
CHAPTER V CONCLUSION AND SUGGESTION
This chapter presents about conclusion of the research. Moreover, suggestion is added in this chapter too.
A. Conclusion
This research was a quasi experiment which was intended to investigate the effectiveness of picture
books in students‟ performance in writing narrative text. After conducting the research and obtaining research result from statistical
calculation, the result showed that there was significant difference in the use of picture books in teaching writing narrative text
in students‟ performance in writing narrative text. This finding could be proved from the result of posttest or
the mean score of posttest in the experimental class which showed that it was higher than the control one. After doing hypothesis testing using independent
sample t-test on IBM Statistics SPSS 19, the result of the calculation found that t
count
2.449 was higher than t
table 0.025
2.009 which was gained based on df = 50 and
⁄ α
= 0.025. It gave a proof that t
count
t
table.
The result of hypothesis test also proved that the significance 2-tailed or the probability value was 0.018.
This result meant that the degree of significance α = 0.05 had to be divided by 2
and proved that Sig. 2-tailed
⁄
α 0.025. Because of obtaining these results, H
was rejected and H
a1
Alternative Hypothesis was accepted. More importantly, the effect size of picture books treatment in students‟ narrative
writing skill was 0.68 and it was on category medium effect based on the effect size range of
Cohen’s d. To sum up, this statistical calculation which was explained above proved that there was a positive effect of using picture books in
students‟ performance in writing narrative text.
