Don't test pupils, talk to them

Teachers are well aware there can be a wide variation in the knowledge and understanding among pupils in a class. When interviewing students in one school, I was told by Y7 (11-year old) pupil Daniel that the three states of matter were 'solid, liquid and gas'. He went on to explain that: 'a solid's particles are close together and they vibrate because all particles move. A liquid's are able to move round more, but they're still attached, and the gas [particles] are as far apart as possible, and they fly around really fast'. 

I imagine that had the class teacher heard this response, she would have been satisfied with the boy's learning and her own teaching. However, another pupil could experience the same teaching with very different results. When I asked Jason what he was studying in the class he said, 'changing states and the three states of matter, and if burning is irreversible, and if "stuff" is a state of matter'. What he had taken away from this was that 'fire is not a state'. When I asked him what the three states of matter are, he suggested 'burning, freezing and melting'.