The title of PB 4 reads: 'How does electricity come to our homes?' Thapelo's has arranged the data on the portfolio board along three focus areas. In the first one he has a picture of a house showing the different rooms and the electrical appliances, plug points, switches and light fittings, and, two diagrams showing parallel and series circuits with
explanations for each:
Parallel circuit:
Each user has its own connector, switch and plug, that is, the current is branched.
If
the one user stops the others carry on working. Homes and streets have this type ofcircuit. The sketch to show this is drawn alongside. (Thapelo)Series circuit:
The current is not branched, the users are connected to a single conducting copper wire connected to the power source.
If
one user is faulty then the current stops flowing to all the other users.(Thapelo)
Thapelo uses the second focus area to drew a diagram to show an 'Electric circuit in the Home'. The diagram is shown below.
Users of electricity; e.g. refrigerator, bulb, iron, television
Mains
Electricity in from source 120Vl...--I---Io-i
Electricity out from users
Picture ofa fridge
Picture ofaTV
Picture of an iron
The lower area of the PB is used to show:
(l) the diagram of an open 3-pin-plug showing the colour coded wire connections and the plug pins. The caption reads: 'This is a diagram showing how to connect a 3-pin plug, showing the correct colour codes'; and
(2) next to the above, a section of three core flex wire, with the 3 individual colour coded wires showing, and the tips revealing a section of copper wire at their ends. The individual copper wires are labeled:
blue - Neutral, brown - Live, and yellow/green - Earth. (Thapelo)
The ideas expressed by Thapelo have a real-word connection. This knowledge that is linked to real life in the learner's home or school explains Perkins' (1992) idea of
generative knowledge. Knowledge that is gained, and cannot be of use to the person who gained it to deal with the world, is wortWess. Teaching, learning and assessment must be organized around meaningful use of content by the learner (Sparks-Langeret al.,2004).
In addition to the above information, Thapelo attached his own handwritten summary on the top right hand corner of the PB which reads:
A. Dangers with electricity 1. overloading adapters
2. leaving un-insulated wires lying around 3. touching a socket with wet hands 4. playing with electricity
5. illegally connecting electricity 6. climbing the pylons
B. Action plan to avoid and prevent these dangers
At home: adapters shouldn't be overloaded in one socket, multiple adapters should be used, children must be taught not to play with electricity.
At school: all classes with bare wires should be reported to educators (number of classes = 5),bare wires should be insulated. The people/government should make sure that the school children know about the dangers about electricity.
In the Community: People should know about the dangers ofelectricity. People should never ever steal electricity,
if
you see someone steal electricity, phone the Eskom crime line 0800 112722. (Thapelo)Thapelo wants immediate action, as he is aware of imminent danger where he lives. This is evident in what he wants to know, and the reason he gave for wanting to learn (See opening paragraph above). Sparks-Langeret al. (2004) assert that real problems do not have a predetermined correct response. They can end up in activism, in which case learners work in the community and/or attempt to improve some local issue in the world around them. The urgency of Thapelo's handwritten plan is confirmation of findings by Krajciket al., (1998) which assert that students were good at generating plans and carrying out procedures. Data obtained form the interviews (focus group and clinical interviews) and learner's reflection diaries reveal the following on what Thapelo has learnt:
Safety measures with electricity in the home; where electricity comes from;
negative and positive charges; how electricity is generated in a power station;
connecting a 3-pin plug to a 3-core flex wire; about negative and positive charges; our homes have parallel circuits for connections; and that parallel circuit is safer (where the other users of electricity continue working if one of them no longer works) than a series circuit. (see Annexture 6, p.226)
Thapelo's view of the role of the teacher as that of someone who assists him in accessing some appropriate pictures, and typing some hand-written learner summaries. Reflecting on the factors that contributed to his learning:
The experiment helped me to learn. It gave me an example on how electricity is produced". (see Annexture 6)
The factors that did not contribute to his learning:
Thapelo shares with us the factors that helped him to learn. Research suggests that learning is maximized if the context of such learning resembles real-life situations in which newly learnt material can be applied to (Brown, Collins and Duguid, 1989).
Thapelo shares his domestic responsibility of baby-sitting as a barrier to his further learning.
4.2.5. Portfolio Board Five (PB 5):
Cameron wanted to know:
Is there life without electricity?
His reason:
1 want to know what to do
if
afriend gets electrocuted, so that1can teach others about safety and the advantages and disadvantages ofelectricity. (see Annexture 6, p.226)Finally, we look at what Cameron put into PB 5, and what learning he took out with respect to insights, attributes, and the science that is reflected in PB 5. Figure 11, on the next page, is a pictorial representation ofthe actual portfolio board (that is, PB 5) constructed by Cameron in consultation with his peers.
The title of PB 5 reads: 'How can we be safe with electricity in our homes? Cameron chose to begin with two pictures, one of woman outside a rural home, with a solar panel outside her mud house, with the caption: 'Left in the dark', and alongside this, is a picture of the President of the country, with electric poles running next to a country road.