Table of Contents
- 1 How do you determine the difficulty level of a test item?
- 2 What is the difference between difficulty index and discrimination index?
- 3 What is a good discrimination index?
- 4 What is the difference between item discrimination and item difficulty?
- 5 How can item analysis improve the test?
- 6 Should items that are too easy or too difficult be thrown out?
- 7 What is item difficulty and item discrimination?
- 8 What is a good point Biserial on an exam?
How do you determine the difficulty level of a test item?
Calculating Item Difficulty Count the total number of students answering each item correctly. For each item, divide the number answering correctly by the total number of students. This gives you the proportion of students who answered each item correctly. This figure is called the item’s difficulty level.
What is the difference between difficulty index and discrimination index?
Item difficulty is the percentage of learners who answered an item correctly and ranges from 0.0 to 1.0. The discrimination index of an item is the ability to distinguish high and low scoring learners.
What is the function of item difficulty to improve the test?
Item difficulty is relevant for determining whether students have learned the concept being tested. It also plays an important role in the ability of an item to discriminate between students who know the tested material and those who do not.
What is a good discrimination index?
11, 12 Discrimination index of 0.40 and up is considered as very good items, 0.30–0.39 is reasonably good, 0.20–0.29 is marginal items (i.e. subject to improvement), and 0.19 or less is poor items (i.e. to be rejected or improved by revision).
What is the difference between item discrimination and item difficulty?
So item difficulty helps us to know the degree to which students get answers correct, whereas item discrimination examines how the top-scoring group of test takers compares to the lowest-scoring group of test takers, another important piece of information to help us know how well our items are working.
How do you use difficulty index?
Using the Difficulty Index Formula The formula looks like this: the number of students who answer a question correctly (c) divided by the total number of students in the class who answered the question (s).
How can item analysis improve the test?
In doing so, item analysis can increase the efficacy of your exams by testing knowledge accurately. And knowing exactly what it is students know and what they don’t know, helps both student learning and instructor efficacy.
Should items that are too easy or too difficult be thrown out?
Items that are too easy or too difficult are discarded; those within a desired range of difficulty are identified.
How can we solve the index of discrimination?
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).
What is item difficulty and item discrimination?
The two most common statistics reported in an item analysis are the item difficulty, which is a measure of the proportion of examinees who responded to an item correctly, and the item discrimination, which is a measure of how well the item discriminates between examinees who are knowledgeable in the content area and …
What is a good point Biserial on an exam?
Values for point-biserial range from -1.00 to 1.00. Values of 0.15 or higher mean that the item is performing well (Varma, 2006). According to Varma, good items typically have a point-biserial exceeding 0.25. As a rule of thumb, items with a point-biserial below 0.10 should be examined for a possible incorrect key.