Lesson 4: Planning

What should we consider as we plan and test designs?

A. Navigation

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What should we consider as we plan and test designs?

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Class design goal: Design 2–3 trellises to keep pea plants off the ground as they grow.

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Based on what we figured out so far, what new ideas can we add about how we’ll know if our trellises are successful?

B. Criteria and Constraints

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Criteria: a checklist for a successful design

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Constraints: limits on the design

• Materials (6’ and 4’ bamboo, twine, coated wire, anything you bring from home)
• Space
• Time to build

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C. Class designs to test

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We will build 5–6 designs to test. We will learn from the tests so we can install 2–3 designs for our pea plants.

What kinds of designs should we test as a class?

Consider the following:

• Initial design ideas
• Design ideas from the gardener interview
• Designs from prototypes

Who wants to build what kind for the class?

D. Successful group work

Working together takes listening to each other’s ideas and compromise. Remember our group agreements.

Watch this video of students designing a tool to lift compost.

• How do they work together? How do they make decisions?
• What is challenging for the group members?

WGBH Educational Foundation, Rights Reserved

E. Plan your group design

1. Plan your design as a group and sketch it in one person’s design notebook. Consider the following:
1. What materials will you use?
2. How will you put them together?
3. What are their main purposes?

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I think we should include _______ (design feature)�because __________ (evidence from prototypes or readings).

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• Develop your construction procedures. What will you build first? What next?

F. Give and receive feedback

Engineers share ideas to improve designs.

• Leave your designs and explanations out and visit another group’s designs.
• Review the other group’s design and provide them with 1 glow and 1 grow.
• Look for evidence about how the design will meet our criteria. How is their design
• helping pea plants climb up them?
• designed so it won’t fall over?
• What is included in the design?
• What is missing?

I noticed that you ________

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Your design shows that you

__________

One suggestion is ________

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You may want to change ________

G. Navigation

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• Next session, we’ll build and start to test whether our new designs work the way we think they’ll work.
• Bring items from home to use in your trellis design if you included that in your plan.

H. Optional what we’ve learned so far

Three students were talking about why this trellis does not move and is stable. Here is what they said.

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Esme: “I think that the forces from the sticks are pushing on each other equally and that is why the trellis does not move.”

Sally: “I think there are no forces acting on the trellis and that is why it does not move.”

Michael: “There is more force pushing on one stick than the others so the trellis does not move.”

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Which student do you agree with the most? Explain your thinking.