Which one of the following is the preferred method for determining item bias?

Correct option is C

The item characteristic curve (ICC) is the preferred method for determining item bias. The ICC is used in Item Response Theory (IRT) to assess how well a test item functions across different groups of test-takers. It evaluates:

• Item bias: Whether an item is easier or harder for certain subgroups of individuals (e.g., based on gender or cultural background) after controlling for ability. A biased item will show inconsistent performance across groups at the same ability level.
• Graphical representation: The ICC plots the probability of answering an item correctly against the ability level of test-takers.

Information Booster:

1. Differential Item Functioning (DIF): ICC helps detect DIF, identifying biased items.
2. Item Response Theory (IRT): A modern psychometric framework that improves test fairness.
3. A non-biased item will show consistent ICC patterns across all groups with similar abilities.
4. Removing biased items improves test validity and fairness.

Additional Information:

• Item difficulty level (Option 1): Indicates how challenging an item is (proportion of correct responses).
• Item discrimination index (Option 2): Measures how well an item separates higher performers from lower performers.
• Inter-item correlation matrix (Option 4): Ensures items measure the same construct but does not assess bias.