Which One Doesn't Belong? Concept Builder is an adjustable-size file that displays nicely on smart phones, on tablets such as the iPad, on Chromebooks, and on laptops and desktops. The size of the Concept Builder can be scaled to fit the device that it is displayed on. The compatibility with smart phones, iPads, other tablets, and Chromebooks make it a perfect tool for use in a 1:1 classroom.


Teaching Ideas and Suggestions:

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:
  • Apprentice Level (easiest): Includes four question groups. Each question includes four representations. All representations describe constant velocity motions.
  • Master Level (moderate difficulty): Includes eight question groups - the four from the Apprentice level plus four new ones. Each question includes four representations.Representations describe both constant velocity and changing velocity motions.
  • Wizard Level (most difficult): Includes 12 question groups - the eight from the Master level plus four new ones. Questions include four or five representations.Representations describe both constant velocity and changing velocity motions.
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. 


Related Resources

There are numerous resources at The Physics Classroom website that serve as very complementary supports for the Which One Doesn't Belong? Concept Builder. These include:
  • Minds On Physics Internet Modules:
    The Minds On Physics Internet Modules include a collection of interactive questioning modules that help learners assess their understanding of physics concepts and solidify those understandings by answering questions that require higher-order thinking. Assignments NL1, NL2, NL3, and NL4 of the Newton's Laws module provide great complements to this Concept Builder. And just about any assignment in the Kinematic Graphing module makes for a great complement to this Interactive. They are best used in the middle to later stages of the learning cycle. Visit the Minds On Physics Internet Modules.

    Users may find that the App version of Minds On Physics works best on their devices. The App Version can be found at the Minds On Physics the App section of our website. The Kinematic Graphing module can be found on Part 1 of the six-part App series. The Newton's Laws module can be found on Part 2. Visit Minds On Physics the App.

  • Curriculum/Practice: Several Concept Development worksheets at the Curriculum Corner will be very useful in assisting students in cultivating their understanding, most notably ...

    Describing Motion with Diagrams
    Describing Motion Numerically
    Describing Motion with Position-Time Graphs
    Describing Motion with Velocity-Time Graphs
    Describing Motion Graphically
    Interpreting Velocity-Time Graphs
    Graphing Summary
    Describing Motion Numerically
    Balanced vs. Unbalanced Forces
    Net Force and Acceleration

    Visit the Curriculum Corner - Kinematics or Curriculum Corner - Newton's Laws.

Additional resources and ideas for incorporating Which One Doesn't Belong? into an instructional unit on Newton's Laws can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.