item analysis which is use for rejecting & accepting the test of items....it is helpful for education & research.

2. ITEM ANALYSIS
PRESENTED BY:
Ms. Preeti Sharma
Msc(N) Prev Yr

3. INTRODUCTION
• It is a statistical technique which is used for
selecting and rejecting the items of a test on
the basis of their difficulty value and
discriminative power.
• Item analysis technique helps in selecting the
best items for final draft of the test and poor
items are rejected and the items are modified.

4. • In addition, item analysis is valuable for
increasing instructors’ skills in test
construction, and identifying specific areas of
course content which need greater emphasis or
clarity. The procedure used to judge the quality
of an item is called as item analysis.

6. “It is a statistical technique which is used for selecting
and rejecting the items of the test on the basis of their
difficulty value and discriminated power”.
“Item analysis is an aspect of test analysis which
involves examination of the characteristics of test
items.”
“The effectiveness of each item can be determined by
analyzing the pupils response to the item, this is known
as item analysis.”

7. PURPOSES
1.To judge the worth or quality of a test
2.Classification of students or candidates.
3.Selection of the candidates for the job.
4.Promotion and prognosis of the candidates or
student
5. To do modification to be made in some of the
items.

8. 6.Brings about improvement in testing methods
and techniques.
7.Make decisions about promotion of students
to the next higher grade
8. To provide discriminatory power to
differentiate between capable & less capable
examinees for the items.
9.To prepare the final draft on the basis of their
difficulty level properly (easy to difficult
items).

9. OBJECTIVES
Toselect the appropriate items for the final draft and
reject the poor items which do not contribute in the
functioning of the test. Some items are to be modified.
Item analysis obtains the difficulty values of all items of
preliminary draft of the test. The items are classified
difficult, moderate, easy items
It provides the discriminative power (item reliability/
validity) to differentiate between capable and less capable
examinees of all the items.

10. The reliability and validity of test depends upon the
characteristics of test. Both these indexes are considered
simultaneously in selecting and rejecting the items of a
test.
Item analysis is a cyclic technique. The modified items
are tried out and their items analysis is done again to
obtain these indexed (difficulty and discrimination). The
empirical evidences are obtained for selecting the items
for the final draft.

11. STEPS
 Arrange the scores in descending order
Separate two sub groups of the test papers
 Take 27% of the scores out of the higher
scores and 27% of the scores falling at bottom
 Count the number of examinees in higher
(N.H) and lower group (N.L)
 Count the number of right answer in higher
group (R.H) and count the number of right
answer in lower group (R.L)
 Count the non response (N.R) examinees.

12. • It involves three numerical indicators. They
are:
 Item Difficulty value
 Item Discrimination power
 Distracter Power

13. ITEM DIFFICULTY VALUE
(D.V)
“The difficultyvalue of an item is definedas the
proportion or percentage of the examinees who
have answered the item correctly”
- J.P. Guilford

14. • Formula:
• R.H= rightly answered in higher group
• R.L= rightly answered in lower group
• N.H= no. of examinees in higher group
• N.L= no. of examinees in lower group
D.V= (R.H+ R.L)
(N.H+ N.L)

15. I.D = R/ N X 100
R= Rightly answered in group
N= total no. of examinees

16. In case of non- response examinees available
means,
• R.H= rightly answered in higher group
• R.L= rightly answered in lower group
• N.H= no. of examinees in higher group
• N.L= no. of examinees in lower group
• N.R= no. of non- response examinees
D.V= (R.H+ R.L)
(N.H+ N.L)- N.R

17. Level of Difficulty
Index Range Difficulty Level
0.00-0.20 Very Difficult
0.21-0.40 Difficult
0.41-0.60 Average/Moderately
Difficult
0.61-0.80 Easy
0.81-1.00 Very Easy

18. ITEM DISCRIMINATION INDEX
(D.I)
“Index of discrimination is that ability of an
item on the basis of which the discrimination is
madebetween superiors and inferiors”. It range
from +1 to -1.
- Blood and Budd (1972)

19. R.H= rightly answered in higher group
R.L= rightly answered in lower group
N.H= no. of examinees in higher group
N.L= no. of examinees in lower group
D.V= (R.H+ R.L)
(N.H) or N.L

20. Types of Discrimination Index
• Positive Discrimination
• Negative Discrimination
• Zero Discrimination

21. Positive Discrimination
An item is correctly answered by superiors & is
not answered correctly by inferiors.
Negative Discrimination
An item is correctly answered by inferiors &
is not answered correctly by superiors.

22. Zero discrimination/
No discrimination
The item of the test is answered correctly by
all the examinee’s or an item is not
answered correctly by any of the examinee.

23. • Ebel’s (1972) gives the indices of item
discrimination in the terms shown below.
For average classroom test, these indices are
widely accepted.
D Value Item Evaluation
0.40 and above very good item
0.30 – 0.39
reasonably good, but subject to
improvement
0.0 – 0.29 marginal items usually needing and
being subject to
Improvement
Below 0.19 poor items to be rejected or improved by
revision

24. DISTRACTOR POWER
• The third statistic is distractor power. It provides
information about effectiveness of the distractors
• Groundlund and Linn 1990 states that this can be
determined by inspection and so there is no need
to calculate index
• In general a good distractor should discriminate
between upper and lower groups

25. EAMPLE:
TOTAL A B C D E
N.H 27 0 7 17 1 2
N.L 27 0 3 7 8 9

26. CONCLUSION
• Thus item analysis is an effective way to
select the appropriate items for the final
draft & reject the poor items which do not
contribute in the functioning of the test.