Skip to 0 minutes and 3 secondsThat's right, that's right. Nat, you've done it wrong. That's right, that's right. Just have a practice go. Go on, move it. Woah. Fantastic. Hey, it worked. 3 seconds. Fair test, there? Do you want to say anything? [INAUDIBLE] Say it, Josh, what's that, go on, Josh. You need to move the fan along with it. What would we change otherwise? How far the fan is. How far away the fan is. The variables that we're going to change later, right.. The wood's getting [INAUDIBLE] Stop! Go on, why is the wood getting heavy? Because it is getting wet and it's absorbed some of the water. Nice, absorbed. And that goes back to our material, doesn't it?

Skip to 1 minute and 8 secondsIt's absorbing, so now we've got water in there as well. All these variables which are hard to control. We can't control everything at the moment in school. But we've got to bear them in mind, haven't we, when we look at the data. Three, two, one, go. Go on. Yes. 5.0, 5.8 seconds. It's also getting bigger. It is getting bigger, go on. So what we were predicting, it's like the opposite to what we got. At the moment it's the opposite to what we thought, yeah. Because when it's bigger, it could be heavier. When it's bigger, it could be heavier. We're going to have a third go. What was that time before though, Josh, hold it there just in case. 5.1 seconds.

Skip to 1 minute and 45 secondsThat was it. So we are starting to go, well, maybe our predictions are wrong here. But there are a lot of other variables in place. We've got to think about that. What have we found out then, guys? Go on, Josh. Smaller sails go faster. The smaller sails go faster. But what was our prediction? Pippa? That the biggest sale would go quicker. Cuz it's the bigger sale. Why did we think that the bigger sale would go quicker? What was the educated guess behind that? We didn't just take a silly guess, we thought about it. Because it's bigger, the wind will be able to hit more stuff. But hit the bigger surface, so it would go faster.

Skip to 2 minutes and 16 secondsYeah, brilliant, we've got more of the air particles hitting the surface. A bit like friction, cuz we were thinking about friction. A smaller area, you generate less friction, so surely a smaller area of the sail, you'd get less wind resistance. But we got the opposite. Why? Give us some reasons, cuz it's not necessarily wrong. Our predictions weren't wrong, but we've got a lot of other things that have been taking place. Why do you think some of this has happened, Max? Because the big ones, they'd be more heavy than the small ones. They'll be lighter than the big ones. Okay, so what are those heavy sails? You're saying it's bigger, therefore it's slightly heavier. And what problem does that cause?

Skip to 2 minutes and 56 secondsCan you be still for a second, Josh? The fan, it'll be more heavy for it to move across the water. Okay, yeah, so maybe a bit more, we call it maybe drag, because of the weight will add a bit more drag to it. What else? Because the fan wasn't straight, and it wasn't heading towards the sail, it was heading to the left. Okay, yeah, so we also have another variable. Not just the size of it, the weight, but the direction the fan caused it to go off and that caused other problems. We kept crashing, and yeah, Layla? The smaller ones would also be easier to control with the fan.

Skip to 3 minutes and 27 secondsOkay, yeah, so the larger it was, the less control we had over it. The smaller it was, we had a bit more control, so we didn't have as much crashing. But it did crash into the side. Scientifically speaking, what force did we have acting also on the boat, then? Friction. Friction, and Max, you mentioned about it being heavier. What was gonna happen to the boat if it was heavier? It would sink. It would sink. And then what other force do we got acting a lot more of? Water friction. Water friction. It's a type of friction, but we call it water. Resistance. Good, water resistance. So we've got a lot that we could question.

Skip to 3 minutes and 55 secondsDo you reckon we could do this test any better? Yeah. What could we do then? What could we do to make it better? Instead of wood, cuz that absorbs water, we could use plastic, cuz it can't soak up water. Brilliant, yeah, we could think about our materials and the properties, so use a less absorbent one. Brilliant answer. I could have held the fan a bit more straight, so it didn't go bumping in to the side. Yeah, that's what we call human error. What would be a good way of presenting this data? Think about how could we present data. What would be a good way of presenting it? A graph chart? Some sort of a graph.

Skip to 4 minutes and 30 secondsWhat kind of graph would would be useful for this? A bar chart? A bar chart maybe, yeah, because we've got single data and we're comparing.

Whole class investigation: investigating

This is the second part of the lesson, where the students put their plans into practice and conduct a scientific investigation. At the end of the video, the teacher discusses one group’s findings.

During this video, you will see the children testing their boats, reporting what they’d found out and making evaluations.

When you carry out investigations in a classroom, try to focus on one area of the scientific process. This may be the planning, the doing or the reviewing stage. In this way the children can work on the appropriate skills for that stage and develop them.

In this example, John was asked to include as many skills possible for you to identify for the purposes of this course. It would not be the norm for him to carry out a whole investigation such as this in one session.

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Whilst you watch the children and teacher working, think about the skills the children are practising. Can you list all the skills that you see?

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This video is from the free online course:

Teaching Primary Science: Getting Started

National STEM Learning Centre