Item Analysis Worksheet
Ten students have taken an objective assessment. The quiz contained 10 questions. In the
table below, the students’ scores have been listed from high to low (Joe, Dave, Sujie,
Darrell, and Eliza are in the upper half). There are five students in the upper quartile and
five students in the lower quartile. The number“1” indicates a correct answer on the
question; a “0” indicates an incorrect answer.
Total
Student
Score
Name
(%)
Questions
1
2
3
4
5
6
7
8
9
10
Joe
100
1
1
1
1
1
1
1
1
1
1
Dave
90
1
1
1
1
1
1
1
1
0
1
Sujie
70
1
1
0
1
1
1
1
1
0
0
Darrell
70
0
1
1
1
1
1
0
1
0
1
Eliza
70
1
1
1
0
1
1
1
0
0
1
rest of class not included in chart
Zoe
60
1
1
1
0
1
1
0
1
0
0
Grace
60
0
1
1
0
1
1
0
1
0
1
Hannah
50
0
1
1
1
0
0
1
0
1
0
Ricky
50
1
1
1
0
1
0
0
0
0
1
Anita
30
0
1
0
0
0
1
0
0
1
0
Calculate the Difficulty Index (p) and the Discrimination Index (D) for each question.
REMINDER: you use the number of the students in both groups when calculating the difficulty
index but the number of students in each group when calculating the discrimination index
# Correct
(Upper
group)
# Correct
(Lower
group)
Difficulty
(p)
Discrimination
(D)
Question 1
4
2
.60
0.4
Question 2
5
5
1
0
Question 3
4
4
.80
0
Question 4
4
1
.50
0.6
Question 5
5
3
.80
0.4
Question 6
5
3
.80
0.4
Question 7
4
1
.50
0.6
Question 8
4
2
.60
0.4
Question 9
1
2
.30
-0.2
Question 10
4
2
.60
0.4
Item
Answer the following questions:
1. Which question was the easiest?
Question 2 was the easiest.
2. Which question was the most difficult?
Question 9 was the most difficult.
3. Which item has the poorest discrimination?
Item 9 had the poorest discrimination index.
4. Which questions would you eliminate first (if any) – why?
Number 9 should be deleted because it was difficult, but the discrimination index of 0.2 meant that low performing students would more than likely get the answer
correct.
5. Is this test overall a good test according to the discrimination index? Calculate the
discrimination values both with and without the questions you may have decided to
eliminate in question 4. Why or why not?
Overall with deleting number 9 this test is a good test. There is a good balance of
difficult and easy question and there is no negative discrimination index.
6. What is the overall difficulty level of this test? Calculate the difficulty values both
with and without the questions you may have decided to eliminate in question 4. Is
this test too easy, too hard, or just right?
The overall difficulty of this test is moderate. This test is just right with question 9
eliminated.