This document discusses analyzing test items to determine their difficulty and ability to differentiate between high and low scoring examinees. It provides guidelines for interpreting facility and discrimination indices. The facility index represents the percentage of examinees answering an item correctly, and discrimination is a number indicating how well an item distinguishes high and low performers. Examples are given of calculating these indices and analyzing item performance based on the results.

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.