PE-CAP: Redesigning Legacy Conceptual Inventories: Summarizing the Quantitative Validation Process

In the ongoing effort to develop a new concept inventory of Newtonian mechanics, context neutral 1-D kinematic and dynamic items were given to students at three R1 universities. Item parameters from Classical Test Theory (CTT) and Item Response Theory (IRT) have been collected on these items over the course of three semesters providing a rich, comprehensive overview of item performance in algebra-based and calculus-based introductory physics courses across pretest and post-test settings. The data shows a substantial difference in item performance between algebra and calculus-based courses suggesting the development and usage of a conceptual instrument should factor in these two populations. The projects' efforts to build subscales out of the tested items using multidimensional IRT, factor analysis, correlation graphs, cognitive diagnostic modeling (CDM), and regression techniques will be presented.