of objective test items is a powerful tool for test improvement. Ahmann and Glock said “Item analysis is reexamining each test to discover its strength and flaw.”
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From those opinions, it can be conclude that item analysis is the process of collecting information about students’ responses to the items to see the quality of
the test items. More specific, item analysis information can tell us if an item was too easy or too hard. Item analysis data also aid in detecting specific technical
flaws and thus further provides information for improving test items. According to James Dean Brown and Thom Hudson, “Item analysis is the
systematic statistical evaluation of the effectiveness of individual test item.”
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Item analysis as a whole will be defined here as the systematically statistical evaluation of the effectiveness of individual test items. Items analysis is
usually done for purposes of selecting which items will remain on future revised and improved versions of test. Sometime, however, item analysis is performed
simply to investigate how well the items on a test are working with a particular group of students, or to study which items match the language domain of interest.
C. Kinds of Item Analysis
There are three characteristics usually considered in the test and measurement, they are:
1. Difficulty Level
Level of difficulty can be identified by selecting the test with percentage of the correct answer. According to Harrison: “Level of difficulty means the
percentage of students who give the right answer.”
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“A good test should have certain degree of difficulty. It may not too easy or too difficult, because the test that is too easy or too difficult for the group tested
yield score distribution that makes it hard to identify reliable differences in achievement levels between members of the group.”
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The level of difficulty is a
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Ahmann, J. Stanley, and D. Glock, Marving, Evaluating Student…, p. 184.
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James Dean Brown and Thom Hudson, Criterion-Referenced Language testing, New York: Cambridge University Press, 2002, p. 113.
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Andrew Harrison, A Language …, p. 128.
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Wilmar Tinambunan, Evaluation of …, p. 137.
percentage of students who answer correctly of the item test. And a good test must be having an appropriate degree of difficulty. So that by analyzing the students’
response to the items, the level of difficulty of each item can be known and the information will be helpful for the teacher in identifying concepts to rethought the
study material and giving the student feedback about their learning. Item difficulty goes by many other names; item facility, item easiness, p-
value, or abbreviated simply as IF.
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To make easier in computing the level of difficulty, the writer divides the students into three groups. They are upper,
middle, and lower groups. Upper and lower group are be focused in analysis and the middle group is aside.
The formula for computing item difficulty is as follows:
Where: FV
: Facility value or item difficulty that we are looking for U
: Sum of students from the upper group who answer correctly
L : Sum of students from the lower group who answer
correctly 2n
: Total sum of students in upper and lower group.
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Based on the techniques above, to find out the difficulty level of all the items in the test by following formula:
Where:
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James Dean Brown and Thom Hudson, Criterion-Referenced…, p. 114.
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J.B. Heaton, Writing English…, p. 153.
FV = Correct U + Correct L 2n
P = ∑ b
N
P : Difficulty level of all items.
b : Difficulty level of each item
∑ ; Sigma Total
N : Total number of test items.
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Score “FV” Facility value or item difficulty that we are looking for and “P” difficulty level of all items can be ranged from 0.00 to 1.00. If “FV” or “P”
is less than 0.30, it means almost the student from upper and lower groups cannot answer the item test correctly these items belong to difficult one. If “FV” or “P”
is 0.30 - 0.70, it means the proportion of students answering correctly is about halfway between a chance value and the point where no student misses the item
these items belong to moderate one. And if “FV” or “P” is more than 0.70, it means almost the students from upper and lower group can answer the item test
correctly these items belong to very easy one.
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.
2. Discriminating Power
