# Identifying physical and chemical change teaching procedure

​The following article was originally written on an online blog as part of the PEEL ASISTM (Australian Schools Innovation in Science, Mathematics and Technology) project. Participants in the project were encouraged to post comments on the blog entries as they appeared. A selection of these responses are included here as they add to the impact of the article.

The article is reproduced with permission from of Peel Publications, Australia, copyright © 2007.

## Using logbooks in year 10 electricity

This idea started with an article written by Nick Berry and John Loughran which appeared in the Australian Science Teachers Journal (September 1994).

We were keen to use a lot of POE (Predict-Observe-Explain) type experimental work in our year 10 Unit on electrical circuits. However, one problem with this approach is that students often are reticent about committing to a prediction and writing it down in fear of ‘writing the wrong thing’ in their books. To avoid this we asked the students to make a special ‘logbook’ out of the (recycled) paper and card we provided.

Students enjoyed making a 10 page logbook and most personalised them with care. Because the logbook was not their regular science book, students were more willing to commit their ideas and predictions to paper.

First we asked the students to draw up a concept map using terms from the unit on static electricity that they had done in year 9. The Logbook helps here because it did not seem to matter as much to get ‘the right answer’ on paper. We then proceeded, using a series of POE experiments to explore the nature of current electricity.

The aim is to introduce and struggle with one idea/concept per lesson.

• Connect a light bulb to a battery to make it light up using only a single wire. Draw how you think it will work first (predict) then find out how you can make it really work (observe). Try and explain what happens in the wires for the light to work (explain).
• Predict the brightness of one, two and three identical light bulbs put in different series. Make the circuits and observe the brightness of the different bulbs then explain the difference (if any) between your observations and your predictions.
• Same for parallel circuits.
• Use different light bulbs. Put them in series. POE.
• Design a method to investigate a factor that affects the resistance of a wire.
• Design a circuit for a specific purpose.

All experiments are designed to bring the students closer to a ‘scientific’ concept of current and resistance. We use a simple supermarket analogy to help students make predictions. The analogy works as follows:

A circuit is like a supermarket…
A bulb is a checkout…..
The battery is an ATM machine…..
The electrons/charges are customers…..

The energy carried by the electrons/charges is like the money they pay at the checkout. Customers can only get one particular amount of money from the ATM (Battery Voltage). Customers must spend all their money at the checkout(s) before they return to the ATM.

We know this analogy can only be taken so far. But it is useful as far as it goes.

The students responded very well to this approach. "Can we please have Logbooks for every topic!” was one comment. When I asked why they liked it, the answers varied from, " You look after them (the logbooks) so we can't lose our work." to "You can see how your ideas about electricity change."

We are now considering where else in the curriculum a logbook approach might be of benefit.