The fit of an item response model is typically conceptualized as whether a given model could have generated the data. We advocate for an alternative view of fit, "predictive fit", based on the model's ability to predict new data. We derive two predictive fit metrics for item response models that assess how well an estimated item response…

This study investigated the effect of the interaction between test takers' background knowledge and language proficiency on their performance on the "TOEFL iBT"® reading section. Test takers with the target content background knowledge (the focal groups) and those without (the reference groups) were identified for each of the 5 selected…

Data from student evaluations of a master's degree program (n=139, 45 percent response) are used to demonstrate four techniques: factor, correlational, discriminant, and multiple regression analysis. Their usefulness in identifying causal factors related to program quality is discussed. (SK)

Research is a useful tool for educators because of its ability to uncover causal relationships between variables that are often obscured in field investigations. This textbook presents basic methodological information that has been designed for and proven to assist the educator who seeks to move himself from the laboratory to the field. The book…