Describe tools used to determine student preconceptions:
This Unit includes the following tools that can help you determine your students' preconceptions:
1. Tool and place in unit:
What We Know About Land and Water and What We Want to Know about Land and Water charts (or KWL chart) Lesson 1.
This tool is designed to draw out preconception from students about Land and Water. Keep these preconceptions in your mind and discuss them during the appropriate lesson.
2. Tool and place in unit:
Lesson 5 Final Activity 2 discussion
This tool is designed to draw out the preconceptions from students concerning the role of different materials and how they are erode and affect erosion. This discussion will allow the teacher an opportunity to see if each student is seeing the connection between the size and weight of the material with how the material is eroded and deposited. If students are not able to articulate this concept, continue to have the students identify the different materials in the following stream table diagrams.
3. Tool and place in unit:
Lesson 7 Final Activity 2 bullet 2 (Or student workbook "Student Instructions for Tracking the Movement of Soil #7".)
This tool is designed to draw out misconception from students about the connection between the speed of the water and whether erosion or deposition occurs. If students bump the stream table or do not correctly identify the speed of the water, a misconception can become more imbedded. It is very important that students experience this concept, and they don't just discuss it.
4. Tool and place in unit:
Lesson 10 Final Activity 1 discussion
This tool is designed to draw out misconception from students about the role of gravity. Have the students discuss how more water means more force to move the soil. However, there is not more gravity because the stream table model is sloped. There is always the same amount of gravity, unless you go into space. However, there is more energy of motion (kinetic energy) because of the increase in slope. Be careful to identify students that think there is an increase in gravity because of the change in slope.
5. Tool and place in unit:
Lesson 14 Final Activity 1
This tool is designed to draw out misconception from students concerning the role of plants in erosion. Some students may think that the soil doesn’t erode because the plants "soak-up" the water. Although this is not entirely incorrect, the main reason that plants reduce erosion is because the roots hold the soil.
Description of a student preconception: During Lesson 1
Preconception: Many students think that the earth’s surface only changes because of earthquakes and volcanoes.
Correct conception by the end of the unit: During Lesson 1
During the discussion, focus on the things that are observable. Make note of which students have this preconception and monitor their thinking throughout the unit. Check for student understanding of the impact of moving water on the Earth’s surface. Corrected preconception: Lots of things, including water, change the Earth’s surface.
Description of a student preconception: Lesson 2
Many students have prior knowledge of the water cycle. However, many students have misconceptions of some stages. Most common misconceptions, steam or seeing your breath when it is cold outside is an example of a gas or water vapor. Steam is not water vapor, it is water vapor that has already condensed, or changed from the gas state to the liquid state. Also, many students think condensation and precipitation are really one step.
Correct conception by the end of the unit: Lesson 2
Condensation is when the water vapor (gas) has changed into liquid water. These tiny liquid drops are not precipitation. I think the confusion is that because the water vapor has changed into a tiny liquid droplet, that it is now precipitation. In order for precipitation to occur, these tiny droplets must bump into each other and form larger droplets. Drops need to be big enough for gravity to overcome the wind and other atmospheric issues then the drops fall to the ground as precipitation.
During Lesson 2, make sure that the students understand that the water vapor is really invisible in their clear plastic box. Also, make sure that the students know that the condensation on the plastic wrap isn’t precipitation. Have them identify condensation AND precipitation in their model.
Description of a student preconception: Lesson 3
Make sure students understand the difference between weathering and erosion. Students frequently think that weathering means that weather caused the material to move. Unless there is a big chuck of packed sand that breaks down into little sand pieces, there is little weathering occurring in this model.
Correct conception by the end of the unit: Lesson 3
Weathering is when rocks and materials are broken down and erosion is when materials are moved from place to place. Make sure during the discussion that students do talk about erosion and weathering correctly. It is very important in this lesson since the sprinkler head is simulating a weather phenomena (rain) in this model.
Description of a student preconception: Lesson 14
Some students may think that the plants stop or slow down erosion because they suck up the water.
Correct conception by the end of the unit: Lesson 14
Although plants do use water out of the soil, the reason plants slow down erosion is because their roots keep dirt particles from being washed away. Also, if the plant drops leaves, the water drops hit the leaves, and the leaves lessen the force that the water droplet hits the earth material, thus limiting the erosion. In Final Activity 1, make sure the students realize that the plants are stopping/slowing down the movement of the soil by the water because of their roots.