Welcome back to our MOOC, teaching science in universities. In the first module we will talk about some fundamental principles of teaching and learning science. Now, we want to apply this and talk about how can we teach scientific concepts. In the first module, we have shown you about the importance of taking every day conceptions and integrating them into science teaching. Now we want to have a closer look at this, which we call conceptual change in science teaching. Conceptual change means that we take students and guide them from the everyday conceptions to more scientific ones. And in the first lesson, we will give some fundamental insights in to everyday conceptions and then we want to show how you can assess your student's everyday conceptions. And in the following lessons we will give some insights of how to productively use these conceptions for science teaching. So how about everyday conceptions? We all hold everyday conceptions in everyday life. And this is a very common thing. For example, think about an apple. I've brought an apple for you and I first like you to complete one of the following sentences. Write down, please write down your conception, write down your conception of whether the apple is alive or not alive. Complete the sentence as following, the apple is alive because or the apple is not alive because. I gave this task to hundreds of students. Hundreds of biology, chemistry, physics, and geography students. And the answers are quite different. Some of the students argue that the apple is not alive because it does not move, it does not breathe, it does not supply it with nutrients any more, or simply because the students don't want to eat things that are alive. On the other hand, some students argue that the apple is alive because it breathes, it can grow, it has a seed in it, or it has metabolism. In everyday situations, it plays no role if we think that the apple is alive or not. But when we come to scientific criteria to scientific settings it obviously plays a role if the apples life or not. And biologists have very strict criteria to argue if something is life the argue via a life functions. Life functions are for example maintaining boundaries. As long as the apple cells have intact boundaries, the apple is alive. As soon as the boundaries break down, the apple dies. Movement, movement is another very life function for biologists. And what does movement mean? If you argue that movement means that something can walk around then, of course, you are right that the apple can never be alive. But for a biologist, movement even takes place in organisms. So if we cut the apple into slices and put them under a microscope, we can see how the fluids and the liquids in the cells are moving. Metabolism, the apple of course has a metabolism. It breathes, it has chemical reactions in it to supply itself with energy. We can see that the apple has metabolism with this apple I've forgotten for two weeks in my kitchen. It's a process of decay that's going on in apples. Of course the apple die somewhere and this is what is happening to this apple. And two more criteria for accessing something is alive or not is reproduction and growth. And reproduction of the apple contains seeds so it can grow again and a new apple tree is born. So, how can we assess these conceptions and how can we use them fruitfully for science teaching? This you will learn in the next lessons.