Psychometric analysis of the resonance concept inventory†

Many undergraduate chemistry students hold alternate conceptions related to resonance—an important and fundamental topic of organic chemistry. To help address these alternate conceptions, an organic chemistry instructor could administer the resonance concept inventory (RCI), which is a multiple-choice assessment that was designed to identify resonance-related alternate conceptions held by organic chemistry students. In this study, two iterations of the RCI were administered to undergraduate organic chemistry students: the RCI-Pilot (N = 484) and the RCI-Final (N = 595). Evidence was collected to support the quality of the RCI items, the validity of the data obtained with the RCI based on internal structure, and the reliability of the data obtained with the RCI. Classical test theory (CTT) was utilized to determine the quality of the items. To gather validity evidence, the Rasch model was used and a differential item functioning (DIF) analysis was conducted. Reliability estimates were made using McDonald's Omega. Since validity and reliability evidence was gathered for the assessment scores, the data obtained in this study supports the use of the 14-item RCI for detecting student alternate conceptions with resonance.