Page 17 - Test Report: Reading and Listening Test for A2 Level
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29 0 0 2 1 0 1 0 0
30 0 1 0 1 2 0 0 0
* Red texts are the correct answer for each item.
4.2.2 Item Discrimination Result
To define the ability of the items to differentiate among test takers on the basis
of how well they know the material being tested. We use this calculation:
Item discrimination = (R.H – R.L)
(N.H or N.L)
R.H – rightly answered in highest group
R.L – rightly answered in lowest group
N.H – number of test takers in highest group
N.L – number of test takers in lowest group
And we separated the item discrimination level into three categories.
Zero discrimination = the item is answered correctly or know by all test takers
Positive discrimination = the item is correctly answered by superiors and not
answered correctly by inferiors
Negative discrimination = the item is correctly answered by inferiors, but not
by superiors
No of correct answers per each group
Item Item Discrimination
High correct Low correct
1 1 0 0.5
2 2 0 1
3 1 1 0
4 2 1 0.5
5 2 1 0.5
6 2 2 0
7 2 1 0.5
8 2 0 1
9 1 1 0
10 2 0 1
