Table 2

Student	Total Score (%)	Questions
1	2	3	4	5
1	90	1	0	1	1	1
2	90	1	0	1	1	0
3	80	0	0	1	0	1
4	80	1	0	1	1	0
5	70	1	0	1	0	0
6	60	1	0	0	0	1
7	60	1	0	1	0	1
8	50	1	1	0	1	0
9	50	1	1	0	0	1
10	40	0	1	0	0	0

Table 2 features the overall scores for the students in the upper and lower group in a class of ten (10) students. In Question #1, there were four (4) students in the upper group who got it correct and four (4) students in the lower group, and the difference between them is zero (0). Since there are ten (10) students total, the number in each group is five (5). So, I would be dividing zero (0) by (5) to get my final result.

After finishing this calculation, the discrimination index score is zero (0), which indicates positive discrimination, so this question is valid and reliable since it's on-topic.

For Practice 2: Try calculating the discrimination index for Question 2 in Table 2, and see if you can calculate that index score (the answer is at the bottom of the page).

You're being asked to complete a test item analysis using Table 2. Follow these steps to determine the Difficulty Index and the Discrimination Index.

1. After the students are arranged with the highest overall scores at the top, count the number of students in the upper and lower group who got each item correct.
2. Determine the Difficulty Index by dividing the number who got it correct by the total number of students.
3. Determine the Discrimination Index by subtracting the number of students in the lower group who got the item correct from the number of students in the upper group who got the item correct. Then, divide by the number of students in each group (in this case, there are five in each group).
4. Record your responses for Questions 3-5 by completing the provided Table below.

Item	# Correct (Upper group)	# Correct (Lower group)	Difficulty (p)	Discrimination (D)
Question 3
Question 4
Question 5

After completing the computations, please answer these four questions based on your test item analysis:

1. Which question was the easiest? Why?

2. Which question was the most difficult? Why?

3. Which item has the poorest discrimination? Why?

4. Which questions would you eliminate first (if any) - why?