Central distractors in Force Concept Inventory data

The Force Concept Inventory was designed to poll the Newtonian conception of force. While there are many in-depth studies analyzing response data that look at the structure of the correct answers, we believe that the incorrect answers also carry revealing information about the students' worldview. The inventory was originally designed so that the "distractors" in each question reflected commonly held misconceptions, and thus the rate at which students guess the correct answer is very low. Students select incorrect answers that correspond to the misconception that they hold and there are very few responses which appear obviously wrong to students. A side effect of this approach is that the incorrect responses reflect the non-Newtonian worldviews held by students. These non-Newtonian worldviews are coherent and robust, and this, at least in part, helps to explain why these misconceptions are so resistant to instruction. In this study we focus once more on the misconception data in Force Concept Inventory responses, particularly on the linkages between these misconceptions. We hypothesize that there are distinct groupings of distractor items formed by the strength of the association between these items. The two largest groupings are associated with the "impetus" world view in which the motion of an object is determined by the quantity of impetus which that object contains. We find that certain central items hold particularly important places in these groupings and also that individual groupings may be connected to each other by "connector" items. We finally suggest that, on the basis of this study, that these non-Newtonian worldviews might best be dismantled by addressing these key central and connector items.