Page 132 - DEDU504_EDUCATIONAL_MEASUREMENT_AND_EVALUATION_ENGLISH

Educational Measurement and Evaluation

Notes is done. What is item analysis ? Item analysis is a process which examines the responses to
individual test items or question in order to assess the quality of those items and the test as a
whole. Item analysis is especially valuable in improving items or questions that will be used
again in later tests, but it can also be used to eliminate ambigous or misleading items in a single
test administration. Specifically, item analysis is the process of finding out the difficulty index,
discrimination index and the effectiveness of distractors. [We will discuss each of these components of item
analysis in detail later].
The quality of a test is determined by the quality of each item or question in the test. The teacher
who constructs a test can only roughly estimate the quality of a test. This estimate is based on the
fact that the teacher has followed all the rules and conditions of test construction. However, it is
possible that this estimation may not be accurate and certain important aspects have been ignored.
Hence, it is suggested that to obtain a more comprehensive understanding of the test, item
analysis should be conducted on the responses of students. Item analysis is conducted to obtain
information about individual items or questions in a test and how the test can be improved. It
also facilitates the development of an item or question bank which can be used in the construction
of a test (Anastasi, 2001).

10.1 Meaning of Item Analysis
The success of a test depends on two factors. First, how successfully a test measures our prescribed
objectives, and second, can each item in the test discriminate between bright and dull students or
not. If a test is not capable of measuring the given objectives meaningfully and discriminating
students, then it cannot be called a successful test.
When a test is constructed, it is begun by noting down the desirable behavioural or personality
trait, and the statements or problems relating to them. As a common rule, the number of these
statements or test items is far larger than the desirable number in the test. It is done so that the
tests found not fit for final inclusion can be deleted. Therefore, an important task of a test-maker
is to verify the test items and select only those which are good enough, reliable, valid and which
fulfil the objectives. This whole process is called item-analysis.
As far as item-analysis is concerned, Freeman has opined that two aspects should be chiefly
considered while undertaking item-analysis : first, the difficulty level of items and second,
discriminating value of test items. According to Guilford, before the final form of the test is
constructed, the method of item-analysis must be applied. The different attributes of the whole
test are dependent on the items included in a test, such as mean variance, form of score distribution,
reliability and validity.
According to Lamark, “The procedure used to judge the quality of an item is called item-analysis.”

10.2 Need of Item-Analysis

The chief objective of item-analysis of a test is to select those items which are suitable, reliable
and valid for that class of students or individuals for whom the test has been constructed. A good
test requires good test items. If the test items of a test are objective-oriented, and are also reliable
and valid, then the test becomes useful. Selecting such items is the purpose of item-analysis.
In brief, item-analysis is needed for the following purposes :
1. Rejecting the items which are weak and have double meaning.
2. Each selected item should represent the whole test.
3. Determining the number of items to be included in the test.
4. Expressing the defects in the responses of the students.

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