Students have already seen how water changes the shape of the land. They have experimented with erosion with a model and outside in their own schoolyard. Now it is time to think about the force of wind in changing the face of the earth.
If you have not done the water and erosion lessons, it may be important to study the term erosion before engaging in this lesson.
I ask students to begin today by reading the I Can statement with me. It reads, "I can create an experiment to test how wind might change the shape of the land."
I say, "today we will work to design an experiment together to help us test if wind can change the shape of the land. We saw how water changed the land so now we will see if wind can do the same. Do you remember the word we used for when the water carried the dirt away?" (Erosion) "We want to see if the wind can cause erosion too. Do you think it can?" (Yes, No) "Please join me on the rug as we think about how we might test whether wind can or can not cause erosion."
"Can anyone tell me what scientists start with when they want to do an experiment?" (a question or an idea) "Can someone give me a question that we can start with?" (Can wind cause erosion? Can wind change the way the land looks? Students will come up with several questions that can then be combined to create a question about whether wind changes the shape of the land.)
One of the important aspects of the NGSS is leading students towards designing their own experiments. In this lesson I want students to take the lead in creating the experimental design. My job is to act as facilitator rather than as dictator as the experiment takes shape. By letting students design the experiment I am not only helping them to see that wind, like water, can change the shape of the land, but I am also teaching students how to set up an experiment to test an idea they have or want to learn more about.
"Now that we have a question, do you remember what scientist do next?" (They predict what they think will happen. They form a hypothesis. ) As students talk about predicting or making a good guess I will reintroduce the term hypothesis if students do not remember it.
"What hypothesis or prediction can we make about wind and the shape of the land?" (That wind changes the shape of the land.) "Now that we have a question and a prediction, how might we go about testing our prediction? Can we brainstorm ways that we might want to test our prediction?"
I encourage students to share their ideas and I record them so we can look at them and try to choose one, or a combination of ideas that we can really do to test our prediction. See Our Brainstorming. I remind students that we have to be able to carry out the idea on our own. We can't get a big machine or robot to do it for us so we need to think about what scientists do when they want to find something out. I hope they will think of models, but if no one does, I may suggest using a model to help us figure out what we want to know.
Once we have a list of ideas, I encourage all students to engage in meaningful conversation about the ideas. I have students turn and talk in groups of 3. I ask each student to choose one idea from the board and tell why they think it is a good idea. They can also combine several ideas if they think that would work better. I give the groups 5 minutes to defend their favorite suggestions. I circulate around to listen in on groups and comment as needed. At the end of the 5 minutes I say, "Now I would like your group to pick the one idea, or combination of ideas that the 3 of you would like to share out with the group. We will then have 6 ideas in all to hear about."
Each group shares 1 idea and I write them on a new piece of paper. We look for similarities in the 3 ideas and I let students defend their ideas in terms of how easy it would be to carry out. We combine any that we can.
Finally I say, "you have heard each group and we have been able to combine some of the ideas into a single experiment. Now you will all have 1 final vote of which design we will use. " I read the final choices and students vote. I read the final choice and ask if there are any last thoughts or is everyone satisfied with our group choice.
I want to make sure that students are interested in the design we have chosen so they stay engaged in the actual experiment.
The students have designed an experiment to use a fan on a pile of sand. They have asked for a bucket of sand, a fan with 2 speeds and a large box. I ask, "what steps will you take to finish your experiment?" I record the steps on the board in the order students say them. We look at them and I ask, "do we need to reorganize the steps at all?" Students make a set of suggestions and then we try to figure out the best order for the steps.
Each group will design a slightly different experiment but if you want the resulting experimental design to go in a given direction, try telling students the materials that are available, ie fan, sand and a box and a ruler and say how can we make a model and see if the wind, generated from the fan can move the land in any way. I limited the students choices of materials to things they would find outside and the fan for the wind and measuring or drawing tools.
This resulted in the generation of the steps below:
1. build a hill with sand and make sure there is no more sand anywhere in the box
2. measure how high the hill is with a ruler
3. turn the fan on low behind the hill to be wind
4. let the fan run on low for 2 minutes
5. measure the height of the hill and see if there is sand anywhere else in the box
6. try again with the fan on high
7. measure the hill height and look around the box for sand that has moved
8. see if the wind changed the hill
I say, "we are going to need to do this as 1 project together. The plan looks like a good one. We can all be the observers but only a few people will be able to do the building, and the running of the fan." We read each step and 1 or 2 students carry out that step and we talk about what we observe before moving to the next step. I choose a student to record what we see in each step. We complete the experiment together in order of the steps we have written on the board. See Discussing What Happened When They Blew on the Dirt on the Mountains.
After students return to their seats I ask, "what did we find out from our experiment with sand and wind?" Students will say that the sand moved, the sand ended up all over the box, etc. See Discussing What We Noticed.
I say, "do you think that the wind outside can do what our fan did?" (yes,no) "Why?" Here I want students to generalize from our model to the real world. I listen for them to give examples of when they have seen the wind move dirt.
I encourage students to tell of times when they might have seen the wind change the face of the land. Making a personal connection to the material helps students to internalize the learning. After letting students share their stories I say, "do you think we can conclude that wind can change the shape of the land, or it can not?" (We can).
In your journal I would like you to tell how wind can change the shape of the land.
After students have had a chance to write in their journals we close with rereading our I Can statement and deciding if we have done what we set out to do. We read, ""I can create an experiment to test how wind might change the shape of the land," and students do a thumbs up if they feel they created an experiment to test how wind might change the shape of the land.