Description of Data An Item Analysis On Discriminating Power Of English Summative Test (An Observation at the Seventh Grade of SMP Al Wathoniyah 09 East Jakarta)
32
35 Number Thirty Five 4.00
36 Number Thirty Six 4.00
L O
W E
R
G R
O U
P 37 Number Thirty Seven
3.80 38 Number Thirty Eight
3.80 39 Number Thirty Nine
3.80 40 Number Forty
3.80 41 Number Forty One
3.80 42 Number Forty Two
3.80 43 Number Forty Three
3.60 44 Number Forty Four
3.40 45 Number Forty Five
3.40 46 Number Forty Six
3.40 47 Number Forty Seven
3.00 48 Number Forty Eight
3.00 Table 4.1 shows that students who are taking the test are classified into 3
groups; upper group, middle group and lower group. The writer took 27 or 13 students from upper and lower group to be analyzed. The highest score in upper
group is gained by one student in score 6.40. The lowest score in upper group is gained by one student in score 4.80. Meanwhile the highest score in lower group
is gained by one student in the same score 4.00. So, the lowest score in lower group is gained by one student in score 3.00.
33
From the table 4.2 in the appendix page 47, it can be concluded that the responses of each item of upper group students in their English test are:
1. There are 13 students who answered the item no 27 and 33 correctly. 2. There are 12 students who answered the item no 9, 12, 17, 21, 34 and 36
correctly. 3. There are 11 students who answered the item no 3, 24, 30, 43 and 45
correctly. 4. There are 10 students who answered the item no 7, 8, 13, 26, 29 and 47
correctly. 5. There are 9 students who answered the item no 1, 10 and 39 correctly.
6. There are 8 students who answered the item no 46 correctly. 7. There are 7 students who answered the item no 2, 22 and 49 correctly.
8. There are 6 students who answered the item no 5, 6, 16, 35, 37 and 40 correctly.
9. There are 5 students who answered the item no 15, 18 and 19 correctly. 10. There are 4 students who answered the item no 11 and 28 correctly.
11. There are 3 students who answered the item no 4, 14, 20, 23, 31, 32 and 38 correctly.
12. There is 1 student who answered the item no 25, 42, 44, 48 and 50 correctly.
13. There is 0 student who answered the item no 41 correctly.
34
From the table 4.3 in the appendix page 49, it can be concluded that the responses of each item of lower group students in their English test are:
1. There are 11 students who answered the item no 30 correctly. 2. There are 10 students who answered the item no 12 correctly.
3. There are 9 students who answered the item no 1, 24, 33 and 36 correctly. 4. There are 8 students who answered the item no 2, 7, 17, 21, 29 and 39
correctly. 5. There are 7 students who answered the item no 3, 8, 15, 20, 27, 34 and 43
correctly. 6. There are 6 students who answered the item no 9, 22 and 47 correctly.
7. There are 5 students who answered the item no 26, 40, 45, 46 and 49 correctly.
8. There are 4 students who answered the item no 4, 10, 13, 37 and 44 correctly.
9. There are 3 students who answered the item no 5, 6, 32 and 50 correctly. 10. There are 2 students who answered the item no 11, 14, 16, 18, 25, 38 and
41 correctly. 11. There is 1 student who answered the item no 23, 28, 31, 42 and 48
correctly. 12. There is 0 student who answered the item no 19 and 35 correctly.
35
Before the writer analyzes the data, the writer has calculated the data into statistic calculation. The writer used Discrimination Index Formula to find the
discriminating power criteria of English summative test. The table is as follows: Table 4.4
The Discriminating Power Index of the Upper and Lower Group Item
Number Total Correct Answer
U - L DI = U - L
Remark Upper
Group Lower
Group 1
9 9
0.00 Poor
2 7
8 -1
0.08 Poor
3 11
7 4
0.31 Satisfactory
4 3
4 -1
0.08 Poor
5 6
3 3
0.23 Satisfactory
6 6
3 3
0.23 Satisfactory
7 10
8 2
0.15 Poor
8 10
7 3
0.23 Satisfactory
9 12
6 6
0.46 Good
10 9
4 5
0.38 Satisfactory
11 4
2 2
0.15 Poor
12 12
10 2
0.15 Poor
13 10
4 6
0.46 Good
14 3
2 1
0.08 Poor
15 5
7 -2
-0.15 Very poor
16 6
2 4
0.31 Satisfactory
17 12
8 4
0.31 Satisfactory
18 5
2 3
0.23 Satisfactory
19 5
5 0.38
Satisfactory 20
3 7
-4 -0.31
Very poor 21
12 8
4 0.31
Satisfactory 22
7 6
1 0.08
Poor 23
3 1
2 0.15
Poor 24
11 9
2 0.15
Poor 25
1 2
-1 -0.08
Very poor 26
10 5
5 0.38
Satisfactory 27
13 7
6 0.46
Good 28
4 1
3 0.23
Satisfactory 29
10 8
2 0.15
Poor 30
11 11
0.00 Poor
N
36
31 3
1 2
0.15 Poor
32 3
3 0.00
Poor 33
13 9
4 0.31
Satisfactory 34
12 7
5 0.38
Satisfactory 35
6 6
0.46 Good
36 12
9 3
0.23 Satisfactory
37 6
4 2
0.15 Poor
38 3
3 0.00
Poor 39
9 9
0.00 Poor
40 6
9 -3
-0.23 Very poor
41 2
-2 -0.15
Very poor 42
1 1
0.00 Poor
43 11
7 4
0.31 Satisfactory
44 1
4 -3
-0.23 Very poor
45 11
5 6
0.46 Good
46 8
5 3
0.23 Satisfactory
47 10
6 4
0.31 Satisfactory
48 1
1 0.00
Poor 49
7 5
2 0.15
Poor 50
1 3
-2 -0.15
Very poor
37
Based on the data above, the percentage of discriminating power English summative test is:
Table 4.5 The percentage of Discriminating Power
No. Discriminating
Power Total
Item Percentage
Item Number 1
Excellent 2
Good 5
10 9, 13, 27, 35, 45
3 Satisfactory
18 36
3, 5, 6, 8, 10, 16, 17,18, 19, 21, 26, 28, 33, 34,
36, 43, 46, 47
4 Poor
20 40
1, 2, 4, 7, 11, 12, 14, 22, 23, 24, 29,30, 31, 32,
37, 38, 39, 42, 48, 49
5 Very poor
7 14
15, 20, 25, 40, 41, 44, 50
The table above shows that there are 0 test item 0 is categorized into excellent test item, which is no showed by the test item number. It is categorized as
excellent test item because its discriminating index is in range between 0.70 –
1.00. There are 5 test items 10 are categorized into good items, that range from 0.40
– 0.70, they are test item number 9, 13, 27, 35 and 45. There are 18 test items 36 are categorized as satisfactory test items for their discriminating index are
in range 0.20 – 0.40, they are test items number 3, 5, 6, 8, 10, 16, 17, 18, 19, 21,
26, 28, 33, 34, 36, 43, 46 and 47.
Meanwhile, 20 test items 40 are categorized into poor test items because their discriminating index are range in 0.00
– 0.20, they are test items number 1, 2, 4, 7, 11, 12, 14, 22, 23, 24, 29,30, 31, 32, 37, 38, 39, 42, 48 and 49.
At last, there are 7 test items 14 are categorized as very poor item as their discriminating index are range in negative values, they are test items number 15,
20, 25, 40, 41, 44 and 50.
38