### Notes:

The Resistance Ranking Tasks 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:

Ranking Tasks is a questioning approach that has been around for some time. Ranking Tasks was popularized as one of several TIPERs (Tasks Inspired by Physics Education Research) by the Two-Year College physics education movement. Such a questioning approach presents students with several variations of a situation that include different variables and require that students rank the variations based on a specific variable or set of variables. In this activity, each situation presented to the student includes three wires. Students must rank the three wires according to the relative resistance. The activity fits well in the early to middle stages of a instructional cycle on voltage, current and resistance.

The Concept Builder includes three activities. 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 activities would be most appropriate for their students. Our summary of the three activities is as follows:

• Resistance and Length: Question Groups 1-3 Three Question Groups, each displaying wires of varying length.
• Resistance and Area: Question Groups 4-6 Three Question Groups, each displaying wires of varying cross-sectional area.
• Putting It All Together: Question Groups 7-12 Six Question Groups, one displaying wires of varying length, one displaying wires of varying cross-sectional area, and four displaying wires of both varying length and cross-sectional area.

We recommend all three activities. The first two activities are rather short and straight-forward. They provide great preparation for the third activity which provides a mix of the two variables that are isolated in Activities 1 and 2. The third activity will require more thinking.

In order to complete an activity, a student must correctly analyze each Question Group in that activity. If a student's analysis is incorrect, then the student will have to correctly analyze the same or very similar question twice in order to successfully complete the activity. This approach provides the student extra practice on questions for which they exhibited difficulty. As a student progresses through an activity, a system of stars and other indicators are used to indicate progress on the activity. A star is an indicator of correctly analyzing the Question Group. Once a star is earned, that Question Group is removed from the cue of questions to be analyzed. Each situation 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 analyze it twice before earning a star. A yellow box is an indicator that the question must be correctly analyzed one time in order to earn a star. Once every question in an activity has been analyzed, the student earns a Trophy which is displayed on the Main Menu. This system of stars and Trophies allows a teacher to easily check-off student progress or offer credit for completing assigned activities.

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 Resistance Ranking Tasks 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. Assignment EC4 of the Electric Circuits module provide great complements to this Concept Builder. 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 Electric Circuits module can be found on Part 4 of the six-part App series. 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 ...

Electrical Resistance

Visit the Curriculum Corner - Electric Circuits

Additional resources and ideas for incorporating Resistance Ranking Tasks into an instructional unit on Electric Circuits can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.