Avoid the use of negatives such as not, except, and least and double
negatives in the stem or alternatives. If negatives are used in the stem, put the as near the end of the stem as possible.
Avoid giving structural clues. This means, not to use one letter for the
alternatives than the other, or make a pattern of a correct response.
Make sure to use “all of the above” and “none of the above” with care. Because, “all of the above” usually have poorer response than “none of
the above”; because all the alternatives must be correct.
Avoid pulling statements directly from textbook. The objective of the test
is for students understanding not memorization.
Alternatives should be plausible to less knowledgeable students. Write distractors with common errors, errors that likely, and erroneous common
sense solution.
3. Kinds of Item Analysis
a. Difficulty Index
The difficulty index is the percentage or proportion of students who answered the item correctly. The Higher the percentage of the
students who answer correctly, the easier the item is.
17
To obtain specific data, the writer differs students into two groups; upper and
lower group. The writer here uses top 27 of high group and the 27 bottom of
the lower group method. The 27 percentage is shown by Truman that it was small enough to clearly identify high and low students group, yet
large enough to provide a sufficient number of score as a base for item statistic.
18
The difficulty index is found quite easy by dividing students who get the correct items with the total number of students whom taking the
17
John C. Ory and Katherine E. Ryan, Tips for Improving Testing and Grading, Los Angeles: SAGE Publication. Inc., 1993, p. 93.
18
Thomas R. Knapp, Statistics for Educational Measurement, Scranton: The Haddon Craftsmen,Inc., 1971, p. 69.
test, after that multiply with 100.
19
The formulation of difficulty index is shown below:
Where: ID: index difficulty
: the number of pupils who answered the item correctly in the upper group
: the number of pupils who answered the item correctly in the lower group
N: the number of pupils who took the test
20
Table 2.1 The classification of Index Difficulty:
21
Difficulty Level 0.00 - 0.30
Difficult 0.30 - 0.70
Medium 0.70 - 1.00
Easy
The test is appropriate for being tested if each item in the examination passed by half of the students.
22
Difficulty Index is relevant for determining whether students have learned the idea of
being tested. It also plays an important role to determine the ability to discriminate the students who know the concept of materials being
tested and those who do not.
b. Discrimination Index
Discrimination index refers to the ability of an item to distinguish among the students on the basis of how well they know the material
19
Arikunto, p. 208.
20
Ibid.
21
Ibid., p. 210.
22
Louis J. Karmel, Measurement and Evaluation in the Schools, London: The Macmillan Company, 1978, p. 381.
