2. Discussing key ideas in groups
Researchers have established a clear link between language and learning. When students discuss ideas with peers, they have time to draw on their memory of what they have done before, share ideas with their partner and clarify their thoughts by having to explain them to others. It also helps them to get used to scientific words which might not be familiar to them. You get the chance to listen to what they are saying and look at what they are writing, so that you are aware of their misconceptions when you plan your questions at the end. You are far more likely to address their misconceptions in this way. Too often when we use questions in a whole class discussion, we assume that because one student can give us a correct answer, the class as a whole understands the topic well. To show that you can use this technique in different contexts, the teacher in Case study 2 gets her students talking about magnetism. Activity 2, which is based on circuits, will take more time than simply explaining the different types of circuit to your class and asking them to copy labelled diagrams and notes, but it will help the students to consolidate their understanding..
Case study 2: Talking about magnetism
Mr Sifuna knows from past experience that students find it difficult to understand the difference between ‘being magnetic’ and ‘being a magnet’ and that they tend to think that all metals will be magnetic. He started the lesson by talking to them about recycling materials. Some students have seen huge electromagnets lifting cars at a local scrap yard. Mr Sifuna showed the class some materials for sorting and asked them to discuss in groups which ones the magnets would pick out. He included empty drink cans, empty food cans, plastic drink bottles, plastic bottle tops, metal bottle tops and pieces of scrap metal. When everyone had made their predictions, he gave each group a bar magnet and asked them to sort the materials into ’magnetic’ and ‘non-magnetic.’
Some of the students were surprised that some of the metal samples were not magnetic.
He then gave each group two magnets, an iron nail, some paper clips and some pieces of copper. He set the question: what is the difference between a ‘magnet’ and a ‘magnetic material’. He encouraged them to experiment with the materials and went round listening to their discussions.
Finally he showed them how an iron nail can be made into a magnet by stroking it in one direction with the bar magnet. Some of the students wanted to know how to separate plastic from copper and aluminium if they are not magnetic (see Resource 3).
Activity 2: Talking about circuits
In exams, students often have to draw or interpret circuit diagrams. They are more likely to do this successfully if they understand the diagrams; simply getting them to copy them down is not the best way to ensure they understand.
Divide your class into groups of six. Give two students in each group a set of descriptions of circuits (Resource 4). One of them reads a description and the other students work in pairs to draw the circuit as described. When they have done five, the students doing the reading out should check the answers. If the pairs disagree then they discuss it as a group until they all agree on an answer. You can extend the exercise by adding ammeters and voltmeters and asking students to work out the current and voltage in different parts of the circuit – depending on your exam syllabus.