1. The Definition of Item analysis
There are several descriptions about item analysis. According to J. Stanley Ahmann and Marvin D. Glock, “Item analysis is reexamining each test item to discover
its strength and flaws”.
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While Anthony J. Nitko, in his book, says that: “item analysis refers to the process of collecting, summarizing, and using information about individual test items,
especially information abut pupils’ response to items”.
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Meanwhile, Harold S. Madsen explains that the selection of appropriate language items is not enough by itself to ensure a good test. Each question needs to
function properly. Otherwise, it can weaken the exam. Fortunately, there are some rather simple statistical ways or checking individuals’ item. This procedure is called
“item analysis”.
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From those opinions, she can conclude that item analysis is the process of collecting information about pupils’ response to the quality of test items.
2. Level of Difficulty
Level of difficulty means the percentage of pupils who answer correctly each test item.
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The percentage is inversely related to difficulty because the larger the fewer will be the students who select the correct option.
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J. Stanley Ahmann and Marvin D. Glock, op.cit., p.184
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Anthony J. Nitko, op.cit p. 284
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Harold S. Madsen, Techniques in Testing, New York: Oxford University Press, 1983 p.180
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J. Stanley Ahmann and Marvin D. Glock, loc.cit
A good test item should have a certain degree of difficulty. It may not too easy or too difficult because the tests that are too difficult will yield score distribution that
make it hard to identify reliable differences in achievement between the pupils who have done well and those who have poorly.
By analyzing the student‘s response to the items, the level of difficulty of each item can be known and the information will be helpful for teacher in identifying
concepts to re-teach the study material and giving the students feedback about their learning.
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Mariane Celce-Murcia says that item difficulty refers to the proportion of correct responses to a test item.
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According to Anthony J. Nitko, item difficulty is the fraction of the total group answering the item correctly. To compute it for each item, add together the number of
students choosing the correct alternative in the upper, middle and lower groups, and then divide this sum by the total number of the respondents taking the test. It can be
stated below:
To make easier in computing the level of difficulty, the writer divides the students into three groups. They are upper, middle, and lower group. Upper and lower
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Antony J. Nitko, op .cit., p. 292
40
Mariane Celce Murcia, Teaching English as a Second or Foreign Language, Boston: Heinle and Hainle Publisher, 1991, p. 495-498
Number of students choosing correct answer P =
____________________________________ Total number students taking test
group are be focused in analysis and the middle group is aside. The writer uses following technique to find out difficulty level of each item in the achievement test:
Where: P
= Level of Difficulty U
= Number of students choosing right answer from the upper group L
= Number of students choosing right answer from the lower group T
= Total number of students in upper and lower group
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Based on the technique above, the writer tries to find out the difficulty level of all the items in Achievement test by the following formula:
Where:P = Difficulty Level of all the items
b = Difficulty level of each item
N = Total number of test items
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Score of ‘P’ can be range from 0.00 to 1.00. If ‘P’ is 0.00, it means there are not students from upper and lower group can answer the item test correctly. These items
belong to very difficult one. And if ‘P’ is 1.00, it means that all the students in upper
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Ngalim Purwanto, Prinsip-prinsip dan Teknik Evaluasi Pengajaran, Bandung: Remaja Rosdakarya, 1986, p. 119
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Aswani Z and Noehi N, Penilaian Hasil Belajar, Jakarta: PAU – PPAI, UT, 2001, p. 176
U + L P = ________
N
∑ b P = ________
N
and lower group can answer the item test correctly. These items belong to very easy one.
To make clear the writer will give the table of difficulty level range as follow:
Table 1 Level of Difficulty
Difficulty Level P
Difficult 0.00 – 0.25
Average 0.26 – 0.75
Easy 0.76 – 1.00
The level of difficulty shows the easiness or difficultness of item test for that group. So the level of difficulty is influenced by the students’ competence. It will be
different if the test is given to another group.
3. The Importance of Item Analysis
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