MediumStatisticsst-164

IRT Item Information

Problem

Return the item information a^2 * P * (1 - P) at theta, where P is the 2PL probability.

Hint

Information peaks where the item is most discriminating.

case 1

in: [0,1,0]

expected: 0.25

case 2

in: [0,1.5,0]

expected: 0.5625

case 3

in: [1,1,0]

expected: 0.19661193324148185

case 4

in: [0,2,1]

expected: 0.419974341614026

case 5

in: [-2,1,-1]

expected: 0.19661193324148185

Starter codePython

import math
def irt_information(theta, a, b):
    # Your code here
    pass

5 test cases · run your code against them in the editor