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The formula to determine the level of difficulty is:
Where : TK : The difficulty level index
B
A
: The number of students with correct answer in group A B
B
: The number of students with correct answer in group B N
A
: The number of students in group A excellent N
B
: The number of students at group B bad
d. Discrimination Index
As stated by Suharsimi Arikunto 2009: 211, discrimination index is the ability of an item to differentiate between high- and low-ability students. In
addition, Ngalim 2009: 120 stated that discrimination index is about how test items can distinguish between the high- and low-ability test takers. From these
opinions, it can be concluded that test items can determine the difference between high- and low-ability students.
The formula to determine discrimination index is::
Notes: DP = the total of test takers
BA = the number of correct answer in the high-ability group BB = the number of correct answer in the low-ability group
NA = the total of students in group A and B Karno, 2003: 14
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According to Karno to 2003:14 the analysis results of the discrimination index in the test of students’ performance in the learning process are:
d. The test items that have enough discrimination 0-29, good 30-
9, and very good 50-100 should be taken into the big book of because its quality has already acceptable.
e. The test items that have low discrimination should be:
a Bad 10-19 could assessed and corrected, and then re-submit it in
the next test of st udents’ performance in the learning process.
b Very bad negative-9 should be casted and not to be included in the
next test of students’ performance in the learning process. According to Anas Sudijono 2011: 408-409, test items with negative
discrimination index should not be included in the next test of students’ performance in the learning process as this kind of items is very low in quality.
e. Distractor Efficiency
Suharsimi Arikunto 2009: 219 stated that what is meant by the distribution of i answer is testee distribution in terms of determining the choice
of answer in the multiple-choice test. The distribution of answer is thought to be good when at least it is chosen by 5 from the total of test takers.
Additionally, Zainal 2012: 279 notes that in a good multiple-choice test, the distractor will be chosen evenly by the test takers. On the contrary, a bad test
will have its distractor chosen unevenly by the test takers. The formula to calculate the index of distractor efficiency is as follow:
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Where : IP : the index of distractor efficiency
P : the number of students that pick the distractors N : the total of the students
B : the number of students with correct answer on every item N : the number of alternative answer
1 : constant numeral Zainal Arifin, 2012: 279
The criteria that can be used to interpret the results of every distractor in an item are as follow:
Very Good IP : 76-125
Good IP : 51-75 or 126-150
Enough IP : 26-50 or 151-175
Bad IP : 0-25 or 176-200
Very Bad IP : more than 200
Zainal Arifin, 2012:280
B. Relevant Study
1. The study conducted by MARZUKI in 2014 entitles “The Analysis of
Test Items of Productive Accounting Even Mid-term Examination for Grade X Students of Accounting Study Program SMK Negeri 1
Yogyakarta Academic Year 20142015”. The results of the study showed that 1 there are 13 items 32.5 that could be considered as valid. 2
