Chapter 7
Item Analysis
Analyze Test Results by Item and Subject
Item Response Theory (IRT) is a method of scoring tests. Although classical test theory methods have been widely used for a century, IRT provides a better and more scientifically based scoring procedure.
Its advantages include:
• Scoring tests at the item level, giving insight into the contributions of each item on the total test score.
• Producing scores of both the test takers and the test items on the same scale.
• Fitting nonlinear logistic curves, more representative of actual test performance than classical linear statistics.
Figure 7.1 Item Analysis Example
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