Shoebox Circuits: A Design-and-Build Capstone Project Helps Students Connect Science with Everyday Life
Sandifer, Cody, Science and Children
Students' eyes grow wide with wonder as they get a motor to work or make a bulb light for the first time. As these daunting feats of electrical engineering remind us, teaching electricity is invariably rewarding and worthwhile. During a typical inquiry-based upper elementary electricity unit, students explore an array of concepts and activities as they attach wires to batteries, install and use electrical switches, and explain the workings of different circuits. Yet as engaging as these learning experiences may be, electricity units sometimes don't quite accomplish the final critical step of science learning: the clear connection of the classroom content to the scientific phenomena in students' everyday lives. This is why the preservice teachers in my elementary science internship course--in which the interns teach inquiry-based science weekly in elementary classrooms--now regularly round out their teaching of a six-hour electricity unit with a capstone project that summarizes and extends the original unit.
In this project, elementary students work in pairs to design and wire a shoe box "room" that meets well-defined circuit requirements. In so doing, the students solidify their understandings of electricity and gain a better understanding of the ways in which electricity concepts are related to the electrical circuits in their homes.
Here we describe the five-phase three-hour project for fourth- or fifth-grade students. The project involves simple circuits, and even teachers new to electricity instruction have been able to implement this project successfully.
To have the greatest potential for success, students should complete a hands-on electricity unit just prior to the project to develop basic concepts related to conductivity, series and parallel circuits, bulb brightness, and switches. These concepts, which will be reinforced as the students plan and build their shoe box circuits, are the following:
* Circuit components such as bulbs, wires, and switches have two distinct ends (connection points), and both ends must be connected to the circuit for the component to function properly.
* Working circuits consist of closed loops that contain an energy or voltage source.
* Switches turn bulbs and other circuit components on and off by completing and breaking, respectively, the circuit loop.
* When bulbs are connected one after the other in the same loop (i.e., in series), each additional component results in less current, and therefore, dimmer bulbs. Switches in a series circuit affect all bulbs in the circuit loop.
* When bulbs are connected to the same voltage source via their own separate (parallel) loops, each bulb experiences the entire voltage of the battery and therefore maintains nearly full brightness. Switches in one loop of a parallel circuit do not significantly affect the bulbs in other loops.
In the project, pairs of students engage in a five-phase process in which they: (1) choose a real-life room (e.g., bedroom, kitchen) to model and generate a circuit blueprint for their model room, (2) test their circuit blueprint to be sure that their planned circuit functions properly (and revise and retest if necessary), (3) install the final version of the circuit into their shoe box room, (4) decorate the newly wired room, and (5) engage in a class discussion and write a brief summative report. Each phase should take approximately 30 minutes, with the exception of the class discussion and brief written report, which will take approximately 60 minutes.
Students should be warned before beginning the project that the open exploration of electric circuits is only safe when done in a supervised school environment. It is not safe for students to conduct this sort of electricity exploration with switches and wall sockets at home. In the classroom, students might inadvertently create a short circuit by having the current bypass the bulbs and travel solely through the wires. …