Item Analysis

Question 1

name all methods of item analysis

Answer 1

1. Item difficulty
2. Item discriminality
3. Item characteristic curves (ICC)
4. Item response theory (IRT)
5. Criterione-Referenced Tests

Question 2

what is item difficulty?

Answer 2

the proportion of people who get a particulr item correct, higher value = easier item
mathematically: no. of people who answered the item correctly/no. of people taking the test

Question 3

what is the optimum difficulty level (ODL)?

Answer 3

ranges between 0.30 and 0.70

halfway between 100% getting an item correct and the success estimated by guessing.

Question 4

What is item Discriminality?

Answer 4

look at whether an item discriminates between different groups taking the test

Question 5

What is the Point-Biserial method?

Answer 5

it’s also known as the item-total correlation, Point-Biserial method is used to distinguish good item from bad items

Question 6

What are item characteristics curves?

Answer 6

the relationship between performance on an item and performance on the overall test tells us how well the item is tapping into what we want to measure. ICCs illustrate this relationship

Question 7

What is item response theory?

Answer 7

it is a different model of psychological testing, a computer generates items and if you answer correctly, the next item will be of increased difficulty, if not, the next item will be of decreased difficulty.
Test performance in IRT is defined by level of difficulty of items answered correctly.

Question 8

What are Criterion-referenced Tests?

Answer 8

CRTs compare performance with some objectively defined criterion