Thinking about what they bring–some ideas to build on: some not
The key challenge of this episode is for the pupils to come to understand how electric circuits work in terms of objects and ideas (such as charge and energy) which they can neither see nor directly experience. The pupils need to be able to explain and model the working of electric circuits in terms of charge, current, energy and resistance.
As youngsters enter secondary school and study electricity, 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, and from their work at primary school, your pupils will have developed some basic 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 pupils 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 pupils do arrive at secondary school with understandings of electric circuits, which are along the right lines and can therefore be built upon in subsequent teaching. Next we consider, in a little more detail, some of the key right lines and wrong track pairs for electric circuits.
Try diagnostic questions
Our experience suggests that there is not a big variation in the views that youngsters of this age bring to their science lessons.
Nevertheless, it is a good idea to probe the understandings of your pupils at the start of any lesson sequence or module, and so we have provided three diagnostic (
think again!) questions, which you might use.
Here are some responses of 11-year-old pupils to the simple circuit
think again questions.
The pupils had just started secondary school and had received no teaching on electricity in the secondary school. These are the verbatim responses of the pupils complete with one or two spelling mistakes!