The wording and structure of questionnaire items can interact with specified sample categories based on evaluation goals and respondent characteristics. The effects of the interactions can restructure samples and introduce bias into the data analysis. These effects, and suggestions for avoiding them, are demonstrated for five types of…

Undergraduates responded to an objective test in electronics and classified each item by domain (one of 14 topics covered in their text), and by type of knowledge (definition, fact, principle, or interpretation). These judgments were compared to their instructor's "standard" judgments. From these data, an index of item-domain divergence…