Student Preconceptions
Describe tools used to determine student preconceptions:
The unit asks students to make drawings of their circuits. It is very important that teachers encourage the use of science notebooks to encourage exploring the question, “How do you think the current is flowing through the circuit?” Have students draw arrows to show the “pathway” - the flow and direction of the current. In summary:
- Ask students to make drawings. Model what a neat drawing should look like and then expect the same type of work from students.
- Date the drawings.
- Have students compare new and old drawings to determine if their ideas about current flow have changed.
Description of a student preconception (naïve conception, misconception, incomplete conception):
In the lighting of one bulb using one wire and one battery, some students will insist that they need two wires. In some sense, this is encouraged by the pre-assessment sheet mentioned on page 10 in the Investigations 2 Folio. Many students will come to the classroom with the notion that the current stops at the bulb. When students begin to construct other circuits with two bulbs and switches, teachers should continue to ask for drawings and have students refer to previous drawing to determine if they have a different model for current flow.
Correct conception by the end of the unit:
Primary Understanding: For a bulb to light, the two battery posts (negative and positive), the tip of the bulb, and the metal terminal must be in a circuit.
Additional Lesson:
Suggested in the Science Extensions for Investigation 2, page 32 of the Folio. If you use a broken 60 watt bulb, students can more easily determine that there is a soldered connection at the side terminal and a metal tip at the base of the bulb, which reinforces that concept that that the current flows through the bulb (instead of stopping at the filament) and back to the battery.
Description of a student preconception (naïve conception, misconception, incomplete conception)
Investigation 2:
Many students will think that the bulb will light as pictured in Response Sheet #9 (Bulbs).
Correct conception by the end of the unit: