Thinking about what they bring–some ideas to build on: some not
The key challenge of this episode is to lay the ground work for developing a model to reason about electric circuits, so that children can explore their thinking. As it takes time to develop and apply a functioning model, its a good idea not to just
tell them how it is. This is even more so if they can neither see nor directly experience what they're trying to model. The model will eventually need to account for the working of electric circuits in terms of charges, current, energy and resistance. That's what expected of children from 11–14 years old.
As children start their exploration of electrical loops, they are already using a wide range of electrical appliances confidently, and very often extremely competently. They take for granted that these things must be switched on, cost money to run, can work from batteries or from being plugged in, can be dangerous and so on. Through these experiences of using electrical equipment, these children will have developed some ideas about how electrical appliances work.
We asked a group of 11-year-olds about their understandings of how electrical appliances and electric circuits work. What they had to say makes for interesting listening!
Right Lines: Complete circuit; no gaps; battery stores energy; electric current is a flow; charge travels; add a battery for brighter bulb; extra battery gives more energy; battery runs out of energy
Wrong Track: Battery stores electricity; electricity from both ends of the battery ; electricity used up; battery runs out of charges; battery runs out of electric currents; shorter connecting wire needs less electricity.
Some of these ideas are consistent with a sound model of electricity and we refer to these as being along the
right lines: complete circuit; no gaps; battery stores energy; charge travels; electric current is a flow; add a battery for brighter bulb; extra battery gives more energy; battery runs out of energy.
Others are not consistent with this view and see the children going down the
wrong track: battery stores electricity; electricity from both ends of the battery; electricity used up; battery runs out of charges; battery runs out of electric currents; shorter connecting wire needs less electricity.
One obvious point is that children do arrive with understandings of electric circuits, which are along the right lines and can therefore be built upon in subsequent teaching.
It's worth keeping these in mind as you plan your own work, so as to guide their thinking off down the right lines.