Robust Structures

• For information regarding general preparation, please see the “Classroom Management” chapter.
• Read about the project so you have a good idea of what to do.
• Define how you want to introduce this project: Use the video provided in the WeDo 2.0 Software, or use material of your own choice.
• Determine the end result of this project: the parameters to present and produce the document.
• Make sure timing allows for expectations to be met.

The introductory video may set the stage for the following ideas to be reviewed and discussed with students.

Introductory video
Here are some suggested talking points for the video:

1. Since it was formed, the earth has been changing shape. Like pieces of biscuit being pushed around on top of a layer of honey, the tectonic plates that compose the earth slide, rub together, and collide.
2. When doing so, the friction creates vibrations on the surface of the earth.
3. During an earthquake, depending on the strength of the vibrations and a variety of other factors, buildings and other structures may be damaged or destroyed.
4. Today buildings are more resistant to earthquakes, thanks to recent scientific discoveries that have led to improvements in design.

Questions for discussion
During the Explore phase, these questions are intended to elicit students’ initial ideas and/or summarise prior learning to evaluate the performance expectation for this project.

Ask the students to document their comprehension, and refer back to these questions again during and after the Create phase.

1. What causes earthquakes and what are the hazards they create?
   Earthquakes are vibrations of the earth’s crust caused by the movement of the tectonic plates.
2. How do scientists rate the strength of an earthquake?
   Scientists rate earthquakes on a scale they call the Richter scale. The higher the number, on a scale of 1 to 10, the stronger the earthquake.
3. What elements can influence the resistance of buildings during earthquakes?
   This answer should serve as the students’ hypothesis. This means that at this point, your students’ answer may be incorrect.
4. What did you notice about the relationship between the size of a building’s footprint and height, and its ability to withstand the impact of an earthquake?
   Structures that are tall or slim are generally less stable and are more likely to fall when submitted to lateral forces.
5. How did you ensure that the tests were kept fair?
   Changing only one parameter at a time.
6. What other factors would be important to investigate?
   Structural design and materials also have to be considered when testing a building’s resistance to earthquakes.
7. How are modern buildings designed to withstand earthquakes?
   Architects and engineers use structures, principles, and simulations to test prototypes for weaknesses.
8. Does “resistant” mean the same thing as “strong”?
   It depends on a variety of factors. Sometimes flexible structures or materials are more resistant than rigid or strong structures.

Ask your students to answer with text or pictures using the Documentation tool.

Build and program an earthquake simulator and model buildings
Students will follow the building instructions to create an earthquake simulator. With this device, they will gather evidence to decide which building would pass the earthquake test.

1. Build an earthquake simulator.
The shake model used in this project uses a piston to push and pull the test plate. The motor power level of the program determines the amplitude of the generated earthquake.

2. Program the simulator.
This program will start by displaying No. 0 on the screen. It will then repeat a series of actions, five times. It will add No. 1 to the display, representing the shake magnitude, turn the motor on to that magnitude for two seconds, and then wait for one second.

Important
With this program, if students want to test a stronger or weaker earthquake, they will need to change the number of loops. Allow them to use a program of their own.

Investigate your building design
Now that students understand the way the earthquake simulator works, let them investigate different factors by isolating one variable at a time.

1. Change the height.
Students should use the short and the tall buildings, both with narrow bases (buildings A and B).

With the tall building on the shaking base, students should find the minimum magnitude that causes the structure to fall. Then, with that same program, they should test if the narrow or short building is more resistant.

Students should be able to discover that with the same base area, the short building is more resistant than the tall building.

Important
Because not all of the motors react exactly the same, it is possible that magnitudes vary, giving different results for each team.

2. Change the width of the base.
With the same program, ask the students to test if the tall building with the narrow base (building B) can resist better than the narrow, tall building with the wide base (building C).
Students should be able to discover that with a larger base area, a tall building is more resistant.

Investigate more with the earthquake simulator
Use the “Investigate more” section of the student project as an optional extension. Keep in mind that these tasks are an extension of the “Investigate” section and are designed for older or more advanced students.

Ask your students to explore other elements that affect the buildings’ resistance to vibration.

1. Change the magnitude.
Ask the students to predict what would happen to buildings A, B, and C if the magnitude of the earthquake was increased, for example, up to level 8. Ask them to record their predictions and test each case.

2. Change buildings.
Applying the fact that a larger base will enable a building to withstand stronger vibrations, challenge your students to build the tallest possible, level-8 earthquake resistant, structure.

Ask the students to explore different building compositions:
• Explore different structural shapes.
• Introduce new materials.

Collaboration suggestion
Allow teams to compare their building designs. Ask one team to describe and test the work of another team:
• What are the structure’s strengths?
• What are the structure’s weaknesses?
• Will the building withstand the earthquake test?

Complete the document
Ask the students to document their projects in different ways:
• Ask the students to take a video of each test they conduct in order to prove their claims.
• Ask your students to compare these conclusions with real-life cases.

Suggestions
Students may collect data in a chart format or on a spreadsheet.
Students may also graph the results of their tests.

Present results
At the end of this project, students should present the results of their investigations.

To enhance your students’ presentation:
• Ask them to describe the factors that influence a building’s stability.
• Ask them to compare these thoughts with their findings.
• Ask them to put their explanations into context.
• Ask them to reflect on their conclusions.
• Discuss whether their results reflect reality.

Scientific understanding assessment rubrics
You can use these assessment rubrics with the observation rubrics grid, which you will find in the “Assess with WeDo 2.0” chapter.

Explore phase
During the Explore phase, make sure each student is actively involved in the discussion, asks and answers questions, and can answer questions about earthquakes in their own words.

1. The student is unable to provide answers to questions or participate in discussions adequately.
2. The student is able, with prompting, to provide answers to questions, participate in discussions, or describe elements that may influence a structure’s resistance to earthquakes.
3. The student is able to provide adequate answers to questions, participate in class discussions, and describe elements that may influence a structure’s resistance to an earthquake.
4. The student is able to extend the explanations in discussion and describe in detail the factors that may influence a structure’s resistance to an earthquake.

Create phase
During the Create phase, make sure that the students use documentation to record predictions and findings, and change only one variable at a time when conducting investigations.

1. The student does not complete the necessary documentation during the investigations and rarely exhibits accuracy in changing only one variable at a time.
2. The student documents his/her findings, but some critical elements are missing, and the student is inconsistent in changing only one variable at a time during the investigations.
3. The student uses adequate documentation to record predictions and findings, or generally exhibits accuracy in changing only one variable at a time during the investigations.
4. The student uses excellent documentation to record predictions and findings or consistently exhibits accuracy in changing only one variable at a time during the investigations.

Share phase
During the Share phase, make sure that each student can effectively utilise documents and verbal communication to explain what is happening with the earthquake simulator, and what can be concluded from the results of the tests.

1. The student offers no explanation, neither in his/her document nor through verbal communication.
2. The student ineffectively utilises documents and verbal communication to explain what is happening and what can be concluded. The explanation may be incomplete or inaccurate.
3. The student ineffectively utilises documents and verbal communication to explain what is happening and what can be concluded.
4. The student effectively utilises documents and verbal communication to offer a sophisticated and accurate explanation of what is happening and what can be concluded.

Presentation and problem-solving assessment rubrics
You can use these assessment rubrics with the observation rubrics grid, which you will find in the “Assess with WeDo 2.0” chapter.

Explore phase
During the Explore phase, make sure that each student can effectively explain their own ideas and comprehension related to the questions posed.

1. The student is unable to share his/her ideas related to the questions posed during the Explore phase.
2. The student is able, with prompting, to share his/her ideas related to the questions posed during the Explore phase.
3. The student adequately expresses his/her ideas related to the questions posed during the Explore phase.
4. The student uses details to extend explanations of his/her ideas related to the questions posed during the Explore phase.

Create phase
During the Create phase, make sure that each student makes appropriate choices (i.e., screenshot, image, video, text) and follows the established expectations for documenting their findings.

1. The student fails to document findings throughout the investigation.
2. The student gathers documentation of his/her findings, but the documentation is incomplete or does not follow all of the established expectations.
3. The student adequately documents findings for each part of the investigation and makes appropriate choices and selections.
4. The student uses a variety of appropriate methods for documentation and exceeds the established expectations.

Share phase
During the Share phase, make sure that each student uses evidence from their own document text and video to explain ideas, including what happened and why.

1. The student does not use evidence from his/her own document text and video and cannot explain ideas, including what happened and why.
2. The student uses some evidence from his/her own document text and video but cannot completely explain ideas, including what happened and why.
3. The student uses evidence from his/her own document text and video to explain ideas, including what happened and why.
4. The student uses a variety of evidence from his/her own document text and video to thoroughly explain ideas, including what happened and why.

To ensure success, consider giving more guidance on building and programming, such as:
• Explain how to conduct an investigation.
• Utilise evidence to construct explanations.
• Offer them additional experiences with isolated variables to test hypotheses.

Also, be specific in establishing expectations for students to present and document their findings.

Suggestion
For more experienced students, allow extra time for building and programming so they can use their own inquiries to design their own investigations. Students could change parameters, such as the level of the earthquake simulator, the materials used to construct the buildings, or the surface on which they test their buildings.

Investigate more
Students will design the tallest building, resisting a grade 8 earthquake. They will apply learnings from the previous investigation.

Possible student misconceptions
Students may believe that earthquakes happen in random locations across the earth. Most of the world’s seismic activity is associated with tectonic plate boundaries. While shallow crevasses may form during an earthquake, due to landslides or ground failures, the ground does not “open up” along a fault line.