In MisstoHit we develop 10 didactic units. All units are tested with at least 50 students from two different countries. NEMO Science Museum is working on a didactic unit about seasons on earth. In June the first concepts of this unit were tested.
What existing knowledge do the students have
The question ‘Why do we experience seasons on earth?’ is a question that is not so easily answered by students. While trying to answer this question with our test students, students reasoned that it had something to do with the orbit of the earth. They explained that the earth does not orbit the sun in a perfect circle, but that the orbit has a more oval-like shape. When the earth is close to the sun, it’s summer, and when the earth is further away from the sun it is winter, they reasoned. A smart explanation indeed, but this common misconception does not explain why the seasons are reversed between the Northern hemisphere and the Southern hemisphere.
Trying instead of explaining
The pupils all received a light bulb and an earth made of pepper foam. With the lights dimmed , they used this model to show how the earth rotates in order to have day and night. For explaining the seasons they were given one extra piece of information: the axis of the earth is slightly tilted, and the North Pole always points (roughly) at the Pole star, in our model a big pointy star drawn the blackboard. Although it proved to be difficult to explain the existence of the seasons by themselves, guided by the right questions at the end of the lesson all students were able to perfectly explain and show when it’s summer in the Netherlands, when it’s winter, why Australia celebrates Christmas with barbecue parties and even why in midwinter the days close to the North Pole only last a couple of hours.
Was the lesson successful?
At the end of the lesson we asked again ‘Why do we have seasons on earth?’. Some students still insisted it had something to do with the oval shape of the orbit of the sun. After extra explanation from disagreeing classmates, they were still confused. Even if they did understand the model, the step from pepper foam ball to actual rotating planets is not so easily made for some.
Was the lesson successful? Yes, we still think it was. It changed their idea on model level. Now they need time to change their ideas in the real world.