3. Encouraging writing
One of the reasons why physics sometimes seems difficult is that we cannot see the things we are talking about. It is full of abstract ideas. You can help your students to understand ideas about physics by making the subject more concrete. You can do this through experiments and models. Giving your students the opportunity to write about their ideas is a very good way to find out what they understand. So getting them to write about an experiment in their own words can really help your students to understand and helps you to see what they do and don’t understand. Resource 5 provides suggestions about how you might use writing to elicit understanding. In Activity 3 you will carry out some demonstrations which your students will explain in their own words. You will provide some key words that you expect them to use and encourage them to use diagrams to explain their ideas. This will demonstrate how particle theory can be used to explain how solids, liquids and gases behave. Case study 3 shows how a teacher uncovered a significant common misconception amongst his pupils and used this to change his lesson plan.
Case Study 3: Using role play to support understanding
Mr Molu asked his class to use the particle model to explain why liquids flow, why solids are hard and why gases can be compressed. He realised when he read what they had written, that there was a lot of confusion, particularly about the liquids and his students did not get very high marks. The students complained that everything in physics is abstract and difficult. He decided to try to motivate the class and make everything as concrete as possible. The previous day he had downloaded a simulation of how particles of solids, liquids and gases are arranged. In a double lesson he started by showing the class the simulation. Then he divided the class into three groups and asked them to role-play the simulations. Each student represented a particle: some students worked together to act being a solid. Others acted being a liquid and or being a gas. They were to report to the entire class how it felt to be solid, liquid and gas. Mr Molu posed the following questions:
- How close are particles in each case?
- How did the particles move in each case?
After this each group discussed and drew the arrangements, which they later redrew on the chalk board. The class was very lively and the students said that for once they experienced joy from being in a physics class.
Activity 3: Effective demonstrations
In this activity you will do some demonstrations that illustrate some of the properties of materials and get the students to explain the demonstrations in their own words. You should write some of the key words on the board. The demonstrations will depend on the equipment that you have, but could include the expansion of a solid when it is heated (ball and ring), the expansion of a liquid when it is heated (coloured liquid in a glass bottle), a needle floating on water, potassium permanganate dissolving in water.
The important thing is to give the students the chance to explain the ideas themselves. Resource 6 gives you some ideas. Use the demonstration to practise your questioning. Start by asking simple closed questions designed to make your students observe carefully and then get them to try and explain their ideas. By giving them the chance to explain the demonstrations in their own words, you will really be able to see if they understand.