35
This is the following of difficulty level result after instrument analysis test:
Table 3.8 Difficulty Level Result
Frequency Category Sum
Percentage No. question
Easy 3
6 3,4,30
Medium 41
82 1,2,6-26,28,31-38,40,42-
48,50 Difficult
6 12
5,27,29,39,41,49
Total
50 100
3. Validity
Validity test is a measurement that confirm an instrument is valid and it can measure what it will be measured Arikunto, 2010: 64 . Validity test that is
used is content validity, so validity test is done by comparing between content with subject material that has been taught. To know the suitability of instrument
with the material, it is done by correlation product moment equations.
r
xy
= items correlation coefficient. X = items scores
N = amount of subject Arikunto, 2010: 72
Here is the interpretation of validity criteria comparing the result to this table.
36
Table 3.9 Validity Interpretation
Correlation Coeficient Validity Criteria
0,80 r ≤ 1,00
Verry high 0,60 r
≤ 0,80
High 0,40 r
≤ 0,60
Enough 0,20 r
≤ 0,40
Low 0,00
≤ r ≤ 0,20
Verry low Arikunto, 2010: 75
This is the following of Validity test result after instrument analysis test:
Table 3.10 Validity Test Result
Frequency Category
Sum Percentage
No.question
Not valid 4
8 10,19,29,42
Verry low 7
14 5,18,31,39,44,47,50
Low 15
30 4,8,13,14,20,21,25,27,28,34,36,41,45,48,
49 Enough
15 30
2,3,6,7,11,12,15,17,23,24,26,32,33,35,43 ,
High 7
14 1,16,22,30,37,40,46
Very high 2
4 9,38
Total 50
100
37
4. Reliability
Reliability test is a measurement which stated about consistence of the measurement tools that is used. Arikunto 2010: 86 stated that reliability tends to
a definition about trusted instrument which is used as collecting data tools because of that instrument has already good. The technique that is used in this research is
used Alpha Cronbrach method because this equation can be used in the answer that has scale or dicotomic scale as like true 1, wrong 0. The split-half method
formula as follow:
Notes : r
11
= Instrument reliability
n = Amount of question
= Amount of Varian score in each item
= Varian total Arikunto,2010:109
The instrument can be called reliable in this technique, if coefficient reliability r
11
0,6 or it can be compared with r table product moment. If Alpha Cronbach reliability coefficient value higher than r table, so that this
r
11 =
[ ] [
∑
]
38
instrument is reliable and vice versa. Here is the table of reliability level to interpreted reliability calculation result :
Table 3.11 Reliability Interpretation
Correlation Coefficient Reliability Criteria
0,80 r ≤ 1,00
Very high 0,60 r
≤ 0,80
High 0,40 r
≤ 0,60
Enough 0,20 r
≤ 0,40
Low 0,00
≤ r ≤ 0,20
Very low Arikunto, 2010: 75
The result of reliability test in instrument analysis test is 0,87. It means that the items test are reliable. The criteria of reliability interpretation is very high.
For recapitulation of all instrument data analysis is displayed in table below:
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Table 3.12 Recapitulation of Instrument Data Analysis Result
No Instrument Test Result
Decision Difficulty
Level Category
Discriminating Power
Category Validity Category
1 0,63
M 0,4
G 0,69
H Used
2 0,6
M 0,27
S 0,42
En Used
3 0,8
E 0,53
G 0,56
En Used
4 0,77
E 0,2
P 0,39
L Used
5 0,17
D -0,2
Neg 0,13
VL Dropped
6 0,4
M 0,47
G 0,47
En Used
7 0,47
M 0,33
S 0,42
En Used
8 0,5
M 0,33
S 0,28
L Dropped
9 0,6
M 0,4
G 0,88
VH Used
10 0,67
M P
-0,58 NV
Dropped 11
0,6 M
0,67 G
0,49 En
Used 12
0,43 M
0,33 S
0,42 En
Used 13
0,43 M
0,33 S
0,37 L
Used 14
0,3 M
0,2 P
0,26 L
Dropped 15
0,4 M
0,47 G
0,47 En
Used 16
0,43 M
0,6 G
0,77 H
Used 17
0,67 M
0,53 G
0,42 En
Used 18
0,7 M
-0,06 Neg
0,04 VL
Dropped 19
0,43 M
-0,47 Neg
-0,28 NV
Dropped 20
0,6 M
0,27 S
0,39 L
Used 21
0,3 M
0,2 P
0,29 L
Dropped 22
0,67 M
0,47 G
0,7 H
Used 23
0,5 M
0,2 P
0,43 En
Used 24
0,33 M
0,6 G
0,58 En
Used 25
0,67 M
0,4 G
0,37 L
Used
40
26 0,47
M 0,93
Ex 0,42
En Used
27 0,1
D -0,2
Neg 0,31
L Dropped
28 0,37
M -0,07
Neg 0,25
L Dropped
29 0,2
D -0,4
Neg 0,13
NV Dropped
30 0,73
E 0,33
Sy 0,65
H Used
31 0,53
M -0,27
Neg 0,01
VL Dropped
32 0,5
M 0,47
G 0,44
En Used
33 0,67
M 0,4
G 0,57
En Used
34 0,47
M 0,27
S 0,28
L Dropped
35 0,5
M 0,47
G 0,4
En Used
36 0,3
M 0,33
S 0,21
L Dropped
37 0,37
M 0,4
G 0,73
H Used
38 0,53
M 0,4
G 0,96
VH Used
39 0,17
D -0,2
Neg 0,13
VL Dropped
40 0,67
M 0,33
S 0,7
H Used
41 0,27
D 0,13
P 0,31
L Dropped
42 0,37
M -0,33
Neg -0,4
NV Dropped
43 0,6
M 0,27
S 0,56
En Used
44 0,53
M -0,27
Neg 0,17
VL Dropped
45 0,57
M 0,33
S 0,37
L Used
46 0,67
M 0,4
G 0,7
H Used
47 0,33
M 0,53
G 0,05
VL Dropped
48 0,47
M 0,53
G 0,42
L Used
49 0,27
D P
0,31 L
Dropped 50
0,63 M
0,2 P
0,16 VL
Dropped
41
G. Research Procedure
