Research School Network: Guiding pupils to work scientifically using the seven step model By Dr Niki Kaiser, Director of Norfolk Research School

Maya rushes home from school, brimming with excitement about her science day. Animatedly, she recounts the exciting experiment they did, where they added vinegar to a tube containing a mysterious powder, causing balloons attached to the tube to inflate on their own.

Maya had a great day at school, and thinks science is really exciting, but despite her exhilarating day, she is left with lingering questions. She wonders why the balloon blew up on its own.

The previous day, the class had burnt wood and melted ice, which she’d seen before outside of school. But the balloon experiment was different to anything she’d seen at home. She understands that melting ice is a reversible change and burning wood is irreversible, but she can’t work out what this has to do with the balloon activity.

Awe and wonder (and scientific understanding)

Practical work is a crucial aspect of science education, engaging learners and fostering understanding, but it’s very easy to get lost in the excitement of the moment, leaving pupils unsure of the science behind it. This is something teachers constantly grapple with, whatever the age of the children they’re teaching. But the recent Primary Science guidance report offers valuable insights for ensuring that children learn the principles of science, as well as experiencing the awe and wonder.

Maya’s balloon activity came at the end of a sequence of demonstrations and activities: it was intended to help pupils distinguish between reversible and irreversible changes. The class had previously mixed sand and sugar with water, and separated them again by filtering the sand and leaving the water to evaporate from the sugar solution. They had also observed matches burning, and had been told it was an irreversible change.

Missed points and misconceptions

But Maya hasn’t quite managed to make the link between the observed changes, or understand fully what the terms mean. She thought that the burning match was an irreversible change, because the match ​“disappeared” when it was burned, and didn’t appreciate that new substances (gases) were formed.

The balloon activity was designed to help explain that some changes result in the formation of new materials, and that this kind of change is not easily reversible, as suggested in the DfE’s National Curriculum document. However, it’s quite a tricky concept to grasp from this particular demonstration, and you have to understand that the gas in the balloon is a new substance, and this is formed when the liquid and powder react.

How could the balloon activity have been delivered to reinforce prior knowledge and help Maya understand how the activities fitted together?

The Seven-Step Model

The Primary Science guidance report recommends a seven-step model for teaching these kinds of lessons. It’s not intended to be a rigid prescription, but it does offer a flexible guide that emphasises activating prior knowledge, explicitly teaching new concepts, and incorporating structured discussions and reflection.

How might the seven steps be applied to this lesson?

1. Link New Learning to Prior Knowledge

To help pupils connect new information to what they already know, remind them of the reversible and irreversible changes they’ve already seen, and encourage them to explain their understanding. Emphasise that when water freezes, it’s still the same substance, but when the match burns, new substances are formed.

2. Explicitly Teach Scientific Concepts

Help pupils to understand that not all new substances are visible. For example, gases are formed when matches are burned, even if it looks like it disappears. Revisiting the concept that air is a substance, and that a balloon actually gets heavier when inflated, could help reinforce scientific knowledge. Breathing on a pane of glass and seeing the gas ​“appear” as it condenses might help here.

3. Modelling

Using visual aids, such as pictures of reversible and irreversible changes, could support understanding by giving a range of examples (and non-examples). Incorporating gases in examples, like pumping up a tyre or shaking a bottle of fizzy drink, could reinforce the concept of gases as substances. This modelling phase encourages students to categorise changes based on their understanding.

4. Memorisation

Reinforce understanding through quick-fire questions and activities like true/​false – thumbs up/​thumbs down. This ensures that students memorise key concepts related to reversible and irreversible reactions and the formation of new substances.

5. Guided Practice

Introduce the practical activity, prompting students to predict outcomes and outlining how they’ll work together to record observations.

6. Independent Practice

Allow students to independently carry out the practical activity and record their observations.

7. Discuss and Reflect

Support pupils to have a reflective discussion about the balloon activity. Encourage them to share thoughts, questions and surprises, reinforcing their understanding. Open-ended questions, such as ​“What did you notice when the balloon inflated?”; ​“How do you think it happened?”. Guide the discussion toward key concepts, such as the production of gases when the match burned, and its connection to this activity.

Reflections

There are opportunities here to bring in other ideas, such as a control variable. How do they know it’s the powder and vinegar that make the balloon inflate? What would happen to the balloon if it was just put on an empty tube? Or on a tube just containing vinegar? How could they test this, and make it a ​“fair test”?

The series of activities described above is quite involved, and would need time. It might be that the first few steps are incorporated into the previous activities and demonstrations – certainly the 7‑step model was never intended to be used as a 7‑step lesson plan!

The final recommendation in the Primary Science guidance report is around the professional development needed to teach primary science. Primary teachers have to be specialists across the range of subjects they teach, and there are some difficult concepts and potential misconceptions even in this relatively straightforward activity. It’s important that colleagues feel confident and supported when they teach.

Awe and wonder – still important

As teachers, we are always trying to strike a balance between sparking excitement and cultivating a deep understanding of scientific principles – both are important. By linking new learning to prior knowledge, explicitly teaching scientific concepts, guiding practice, and encouraging independent reflection, we can help our pupils experience them side by side. The seven step model can help us to do this.