Item Cloning Variation and the Impact on the Parameters of Response Models

Area of Science:

• Psychometrics
• Educational Measurement
• Psychological Research Methodology

Background:

• Item cloning, creating similar but varied test items, is common in educational and psychological research.
• This practice can introduce unintended variations in item difficulty, posing psychometric challenges.
• Existing models may not adequately account for these subtle difficulty shifts.

Purpose of the Study:

• To investigate the psychometric implications of item cloning.
• To evaluate how variations in item clone difficulty affect measurement models.
• To propose and test models that address these psychometric issues.

Main Methods:

• Development of four distinct psychometric models to represent item cloning variations.
• Simulation studies were conducted under various conditions of item difficulty variation.
• Analysis focused on the propagation of variance and resulting parameter biases.

Main Results:

• Unaccounted variance in item clone difficulty leads to predictable bias patterns in model parameters.
• Person parameters demonstrated relative robustness across different models.
• Item parameters were significantly affected, with model choice being critical for accurate inference.

Conclusions:

• The choice of psychometric model is critical when dealing with item cloning.
• Specific models can help identify and mitigate biases caused by item cloning.
• Careful consideration of item cloning effects is essential for valid inferences in assessments.