This Concept Builder is intended for use near the early to middle stages of a learning cycle on Newton's second law of motion. Its strength is in helping students associate the relative strength of the forces acting upon an object to the state of motion of the object. We believe that is can be an effective activity if used anytime during a Newton's Laws unit once the first and second laws have been introduced and discussed. The goal of the activity is to help students relate representations of an object's motion (position-time graphs, velocity-time graphs, verbal descriptions, dot diagrams, and data tables) to the relative strength and direction of the forces that act upon the object.
 

This Concept Builder is intended as an in-class activity. After some discussion of the second law and some review of kinematic representations of motion, allow students an opportunity to interact with the questions. The Concept Builder includes three levels of difficulty. Teachers using the Concept Builder with their classes should preview the activity (or view the Questions in the separate file) in order to judge which levels would be most appropriate for their students. Each question presents four to five representations to students; they must identify which one is not consistent with the others; that is, which one doesn't belong.

Our summary of the three levels is as follows:

We can imagine it being profitable to allow students to make judgements as to what level to begin with and to progress from easier to more difficult levels. 

In order to complete a level, a student must correctly answer one question from each question group at that level. If a student's answer is incorrect, then the student will have to correctly answer the same or very similar question twice in order to successfully complete the level. This approach provides the student extra practice on questions for which they exhibited difficulty. As a student progresses through a level, a system of stars and other indicators are used to indicate progress on the level. A star is an indicator of correctly answering a question from within that question group. Once a star is earned, that question group is removed from the cue of question groups to be analyzed. Each question group is color-coded with either a yellow or a red box. A red box indicates that the student has incorrectly analyzed the question and will have to correctly answer it twice before earning a star. A yellow box is an indicator that the situation must be correctly answered one time in order to earn a star. Once every question group at a level has been answered, the student earns a medal which is displayed on the Main Menu. This system of stars and medals allows a teacher to easily check-off student progress or offer credit for completing assigned levels.

The most valuable (and most overlooked) aspect of this Concept Builder is the Help Me! feature. Each question group is accompanied by a Help page that discusses the specifics of the question. This Help feature transforms the activity from a question-answering activity into a concept-building activity. The student who takes the time to use the Help pages can be transformed from a guesser to a learner and from an unsure student to a confident student. The "meat and potatoes" of the Help pages are in the sections titled "How to Think About This Situation:" Students need to be encouraged by teachers to use the Help Me! button and to read this section of the page. A student that takes time to reflect upon how they are answering the question and how an expert would think about the situation can transform their naivete into expertise.