  Newton's third law is one of the most important concepts learned early in
introductory mechanics courses; however, ample studies have documented a wide
range of students' misconceptions and fragmented understandings of this concept
that are difficult to change through traditional instruction. This research
develops a conceptual framework model to investigate students' understanding of
Newton's third law through the knowledge integration perspective. The
conceptual framework is established with a central idea emphasizing forces as
the outcomes of an interaction instead of using the common action-reaction
language. Additional studies to apply this conceptual framework in assessment
and instruction will follow.
