Item Characteristic Curve

An Item Characteristic Curve (ICC) is a graph used in testing to show how likely a person is to answer a question correctly based on their ability level. It plots the probability of a correct response against different skill levels, helping to understand how well an item discriminates between different capabilities. For example, easier questions have higher chances of being answered correctly by most people, regardless of ability, while harder questions are only answered correctly by those with higher skills. This curve helps test creators evaluate and improve questions to better measure what test-takers know.