F. Technique of Analyzing Data
To find out the effectiveness of picture storybook on students’ vocabulary
mastery at the seventh grade of SMP Kartika VII-1 Cijantung, the writer uses T-test. The writer uses the formula that is independent sample T-test.
Because the sample that the writer use is independent sample, and they are in small sample size.
8
t
o
=
t
o
: t value
M
1
: Mean of experimental group gained score
M
2
: Mean of controlled group gained score
SE
M
: Standard Error of experimental class
SE
M
: Standard Error of controlled class
The procedure of calculation as follows
9
: a.
Determining Mean I with formula:
Mean Variable X M
1
= b.
Determining Mean II with formula:
Mean Variable Y M
2
= c.
Determining of Standard Deviation of Variable X :
SD
1
=
8
Anas Sudijono, Pengantar Statistik Pendidikan, Jakarta: PT Rajagrafindo Persada, 2014, pp. 314-316.
9
Ibid.
d. Determining of Standard Deviation of Variable Y:
SD
2
= e.
Determining standard of error mean of variable X:
SE
M
=
f. Determining standard of error mean of variable Y:
SE
M
=
g. Determining standard of error mean difference of M
1
and M
2
:
SE
M - M
= h.
Determining t
o
with formula: t
o
= i.
After getting the t
o
or t
observation
, it is necessary for determining degree of freedom df with formula:
df = N
1
+ N
2
– 2 Note:
Variable X: Students who are taught by using picture storybook Variable Y : Students who are taught without using picture storybook
G. Statistical Hypothesis
The hypothesis of the study can be formulated:
1. Null Hypothesis H
o
: “There is no significance difference of students’ vocabulary mastery
between students who are taught by using picture storybook and students who are taught without using picture storybook.
” 2.
Alternative Hypothesis H
a
: “There is a significance difference of students’ vocabulary mastery
between students who are taught by using picture storybook and students who are taught
without using picture storybook.”
The result of t-test can be seen with the criteria: a.
If t
o
≥ t
table
, it means there is significance difference and H
a
accepted, H
o
is rejected. b.
If t
o
≤ t
table,
it means, there is no significance difference and H
a
is rejected, H
o
is accepted.
30
CHAPTER IV RESEARCH FINDING AND INTERPRETATION
In this chapter, the writer analyzed and interpreted all data which were collected during the research. This chapter was divided into 4 subchapters: Data Description,
Data Analysis, Hypothesis Testing, and Interpretation of data.
A. Data Description
In this chapter, the writer displayed the description of pre-test and post-test data. The data were collected from students’ pre-test and post-test in both two
classes, experimental and controlled class. To find out the result of the test Pre-test and post-test the writer made the
table of the students’ score as follow:
Table 4.1 The Score of Pre-test and Post-test Experimental Class
Students Pre-test
Post-test Gained Score
1 30
66 36
2 56
76 20
3 56
66 10
4 46
50 4
5 50
76 26
6 56
80 24
7 60
70 10
8 56
86 30
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