Analysis of Student Understanding of Force Using the Dynamics Concept Inventory, Think-Alouds and Confusion Matrices

Concept inventories have been used to measure student understanding of different concepts in many different courses. They are designed to have distractors to help those evaluating student responses identify where there may be misconceptions. But it still may be difficult to determine a student's thought process at the time they answered the question. In this study we use a combination of Think-Alouds and Confusion Matrices to evaluate student responses to questions regarding Force applied to particles and rigid bodies in the Dynamics Concept Inventory. A Think-Aloud is a recording of a student expressing their thoughts aloud while taking an exam. A confusion matrix is a 2x2 matrix with column headings scoring Student Oral Reasoning as correct or incorrect and row headings scoring Question Outcome as correct or incorrect. It is expected to illuminate the influence of luck versus true understanding. Preliminary Analysis indicates students have a strong understanding how forces effect particle motion before and after a dynamics class, but they are more challenged when thinking about rigid bodies.