Some Physics teachers may recognize this Concept Builder as a CASTLE-inspired resource. And indeed it is. CASTLE (Capacitor-Aided System for Teaching and Learning Electricity) is a lab-centered Physics curriculum that has become popular in high schools for approaching the topic of electric circuits. One of the earliest sections is titled What Is Happening in the Wires? The goal of this section is to understand that charge flows in the wires at the same rate at every location. Conventional current is introduced and its direction is defined. The arrowtail notatoin and starburst notation are used as representations for bulb brightness and current.

Whether a teacher uses the CASTLE curriculum or not would have no bearing upon whether or not this Concept Builder is used. While it is CASTLE-inspired, it is not CASTLE-dependent. The Concept Builder is easily complemented by hands-on approaches that fall outside of the CASTLE curriculum. You will find some of those activities in The Laboratory section of our website. This Concept Builder supports what is a primary goal of any circuits curriculum - that current in a circuit is everywhere the same and dependent upon the amount of voltage impressed across its ends and the amount of resistance located between its ends.

This Concept Builder consists of 50 different questions that are grouped into 18 different Question Groups and spread across three different activities. Those three activities are described as follows:

• Fundamentals: Question Groups 1-6. Students must express and understanding of current's conceptual and mathematical meaning, its direction, and the fact that it is the same at every location in a circuit
• Case Studies: Question Groups 6-12. Students are provided a circuit with information about bulb brightness and current. They must predict how the bulb brightness and current would be affected by changes in the number of bulbs, the number of cells, and the resistance of a bulb.
• Law Breakers:  Question Groups 13-18. Students are presented with three circuits. They have varying number of cells and varying number of bulbs (in series). Information about current direction and amount at various locations and about bulb brightness is presented. Students must determine which representation violate a concept about current.

Before using the Concept Builder with your classes, we recommend that teachers attempt each of the activities in order to determine which are most appropriate for your classes and what pre-requisite understanding a student must have in order to complete it. Alternatively, the questions are provided in a separate file for preview purposes. 

In order to complete an activity, a student must correctly analyze each question 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 level. A star is an indicator of correctly analyzing the question. Once a star is earned, that question 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. 

 

 

There are numerous resources at The Physics Classroom website that serve as very complementary supports for the Electric Circuits Concept Builder. These include:
 

 

 

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