Why do we nee to analyze the items of the test?

2. “Why do we need to
analyze the items of
the test?”
Assessment- it is description,
or explanation of something,
usually based on careful
consideration or investigation.

3. “Purpose of
assessing the item”
To determine
its difficulty.

4. How to Analyze
the Item?
1. Facility index – the percentage of examinees who
correctly answer an item. The higher the index,
the easier is the item.
Guide for interpreting the facility index:
81-100% correct - very easy
61- 80% correct - easy
41- 60% correct - Average facility
21- 40% correct - Difficult
0- 20% correct - Very difficult

5. 2. Discrimination index – this is a number
which indicates the ability of an
item to differentiate between
high and low scorers on the test
Guide for interpreting discrimination index:
Index
≤ 0.0 - negatively or not at all
discriminating
.01 - .15 - very low discrimination
.16 - .30 - moderately discrimination
.31 - .45 - good discrimination
> .45 - highly discrimination

6. Sample of Difficulty
Index
Item No. 1
Option Freq. % Valid Cum
percent Percent
*A 341 93.2 93.2 93.2
B 1 .3 .3 93.5
C 4 1.1 1.1 94.6
D 20 5.4 5.4 100
TOTAL 366 100 100

7. Option Analyses
Item No. 1
Option Freq. % The correct key (A)was chosen by
93.2% of the examinees. This item is
*A 341 93.2 too easy; perhaps option A is very
B 1 .3 obviously the correct answer Option B is
not performing as an option. It was not
C 4 1.1
plausible enough. C is also a poor option.
D 20 5.4 (To be considered plausible, an option
TOTAL 366 100 must be chosen by at least 3% of the
examinees)
Item No. 2
Option Freq. % Item 2 suggests a possibly wrong key.
Or it could imply misconceptions because
A 2 .5
B is just too attractive an answer. The
B 340 92.3 key should be reviewed. The item too,
*C 16 4.8 because it might only have been
misunderstood.
D 8 2.4
TOTAL 366 100

8. Item Analysis on 30 Item
N = 780

9. N= 780
H = 27% OF 780 = 210
B = 27% OF 780 = 210
Formula:
FI = (h + b) X 100%
(H + B)
DI = (h - b)
H

10. Distribution of Numbered Items Accdg. To
Facility and Discrimination Indices
Facility
Index DISCRIMINATION INDEX
(%) Neg.-.00 .01 - .15 .16 - .30 .31 - .45 .46 - .60 > .61 Total
81 – 100%
61 – 80 % 4 2, 10 6, 13, 24 11, 14 8
41 – 60% 16 5 23, 17 29 1 3, 7, 20, 22 10
21 – 40% 25 26 15, 27 4
0 – 20% 9, 12, 17 8, 18, 21, 19 8
30
Total 5 6 4 5 4 6 30
The frequencies inside the green box are
those of acceptable items.