Development and psychometric analysis of an inventory of fundamental concepts for understanding organic reaction mechanisms

Abstract The fundamental concepts for organic reaction mechanisms inventory (FC-ORMI) is a multiple-choice instrument designed to assess students’ conception of fundamental concepts for understanding organic reaction mechanisms. The concepts were identified from open-ended interviews and a national survey of organic chemistry instructors reported in a previous study. This manuscript describes the development of the inventory items related to these identified concepts and the psychometric analysis of the instrument. In the developmental stage, open-ended questions were administered to first-semester organic chemistry students (N = 138), and open-ended interviews were conducted with students (N = 22) from the same pool to gain insight into their thought processes. The answers revealed alternate conceptions which were used to formulate distractors for the inventory. A pilot version and a beta version of the inventory were administered to 105 and 359 first-semester organic chemistry students, respectively. From these administrations, the 26-item alpha version was developed and administered to first-semester undergraduate organic chemistry students (N = 753). Psychometric analysis was conducted at the item and test level using Classical Test Theory and Rasch analysis. The results indicate that the items on the FC-ORMI function well to reveal students’ alternate conceptions. The instrument meets the acceptable standards of validity and reliability for concept inventories.