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Bike Shop 3-5 / Week 12 / Wednesday
3/6
Week 12 · Design a Better Bike

Wednesday

Compare and choose
// Define, compare, test, improve
⏱ about 15 min

Wednesday: Compare and Choose

Rocket loves idea three, a basket shaped like a rocket. "That one wins!"

Raven points at the criteria list. "What do you notice? Does it hold three books?"

Rocket frowns. "It is pointy. Books would slide out."

Nova hovers over the three sketches. "Compare each idea with your criteria," she says. "Then decide."

Compare with the criteria

Engineers compare ideas by how well each meets the criteria and constraints.

A table helps. Give each idea a score for each criterion.

The coolest-looking idea is not always the best fit.

Idea (made-up practice scores)Holds 3 booksBooks stay putUses only cardboard and tapeTotal
Rocket basket1124
Box basket2226
Strap net2103

In this practice table, 2 means great, 1 means okay, and 0 means no.

READ THE PRACTICE SCORES
  • Read the question.
  • Tap your answer.
These are made-up practice scores. Which idea has the highest total?
Why does the strap net get 0 for materials?
Which idea scored lowest for keeping books put?
In the practice table, what is the box basket's total score?
WHY THIS EXERCISEThe box basket scores 2 plus 2 plus 2, which is 6.
StatementTrue or false?
The coolest idea is always the best fit.?
Ideas are compared using the criteria.?
An idea that breaks a constraint loses points.?
Rocket was wrong to love his idea.?
WHY THIS EXERCISEEngineers compare ideas fairly, and every idea teaches something.
Try it
Make a score table for your own three ideas.
Use 2 for great, 1 for okay and 0 for no.
Add up each row. Circle your top idea.
Safety first
Paper and pencil only today.
My ideaCriterion 1Criterion 2Constraint met?Total
Idea 1
Idea 2
Idea 3
Practice score for the rocket basket total: ____.
Practice score for the strap net total: ____.

Smart choosing! Tomorrow you build a model and run a fair test.

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