Definition of Item Analysis
Item Analysis refers to a statistical process used in educational and psychological testing to evaluate the quality of individual test items or questions. It involves analyzing the performance data of a group of test takers to assess item difficulty, discrimination, and effectiveness.
Item Difficulty
Item difficulty, also known as item facility, measures the proportion or percentage of test takers who answered a specific item or question correctly. It helps determine how easy or difficult an item is for the group of test takers.
Item Discrimination
Item discrimination assesses how well a particular item differentiates between high and low performing test takers. It measures the extent to which the item identifies those who have a greater level of the construct being tested and those who have a lower level.
Effectiveness of Items
The effectiveness of items is measured by examining their psychometric properties, such as reliability and validity. Reliable and valid items are crucial to ensure accurate and meaningful assessment results.
Purpose of Item Analysis
Item analysis serves multiple purposes, including:
- Identifying poorly performing or ambiguous test items that may need to be revised or eliminated
- Evaluating the overall quality and difficulty level of a test
- Improving the reliability and validity of assessments
- Informing item selection and development for future test administrations