Page 138 - DEDU504_EDUCATIONAL_MEASUREMENT_AND_EVALUATION_ENGLISH

Educational Measurement and Evaluation

Notes Difficulty Level Index

Higher Group Inferior Group Joint Difficulty Index

Item Number of Difficulty Number of Difficulty (R = R )
H L
No. right responses index (R ) right responses index (R )
H L
1. 5 5/5 1.00 3 3/5 .60 1.60 .80

2. 5 5/5 1.00 3 3/5 .60 1.60 .80
3. 5 5/5 1.00 3 3/5 .60 1.60 .80
4. 3 3/5 .60 2 2/5 .40 1.00 .50
5. 5 5/5 1.00 1 1/5 .20 1.20 .60
6. 5 5/5 1.00 0 0/5 .00 1.00 .50

7. 2 2/5 .40 1 1/5 .20 0.60 .30
8. 3 3/5 .60 1 1/5 .20 0.80 .40
9. 4 4/5 .80 1 1/5 .20 1.00 .50
10. 4 4/5 .80 1 1/5 .20 1.00 .50

11. 4 4/5 .80 1 1/5 .20 1.00 .50
12. 5 5/5 1.00 3 3/5 .60 1.60 .80
13. 5 5/5 1.00 3 3/5 .60 1.60 .80
14. 3 3/5 .60 3 3/5 .60 1.20 .60

15. 1 1/5 .20 3 3/5 .60 0.80 .40
16. 4 4/5 .80 3 3/5 .60 1.40 .70

R H + R L
Difficulty Index (D.I.) =
2
Where, D. I. = Difficulty Index
R = Right responses in Higher Group
H
R = Right responses in Lower Group
L
In the above table, the items with .80 difficulty index is the easiest and with .30 is the most
difficult.
In order to calculate discriminating value, the difference between the number of right responses
in the two groups is found out. This is called the discrimination index or validity index (V.I.).
This is,
V.I. = R – R (N being the same for both groups)
H L
The following table displays the discriminating value or validity index :

132 LOVELY PROFESSIONAL UNIVERSITY