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Unit 5 of 6 · about 22 min

Brainstorm, Model, Choose

Lots of ideas, cheap models, and a fair way to pick the best one

📖 Read 🔤 Words to know 🛠 Mini activity ✅ Check

Open up, then narrow down

Steps 3 and 4 of the design process are opposites, and that is the point. First you open the problem as wide as you can: develop alternative solutions, as many as possible. Then you narrow it back down to one: select the best solution. Doing both at once is how good ideas get killed before anyone sees them.

Open up, then narrow down. Brainstorming opens the problem wide: many ideas, no judging. Choosing narrows it back to one: constraints knock out ideas that cannot work, then criteria rank the rest. Mixing the two phases is how good ideas get killed too early.

Brainstorming

Brainstorming is a group way to collect ideas fast. The rules are simple and strict:

•Go for quantity. Twenty ideas beat three.

•No judging while ideas are coming. Not even a face.

•Wild ideas are welcome. A silly idea often has a sensible one hiding inside it.

•Build on each other. "Yes, and…" beats "but."

•One person writes everything down where everyone can see it.

Judging comes later, on purpose. When you are working alone, sketching does the same job: quick drawings on one page, no erasing, each one a different way to solve the problem.

Models: cheap ways to see an idea

You cannot compare ideas that exist only in someone's head. Models make ideas visible and testable before you spend real material.

Model	What it is	What it is good for
Sketch	A fast drawing, minutes, free	Getting ideas out and comparing them
Rendering	A careful, realistic drawing with color and shading	Showing what the final thing will look like
Appearance model	A 3D model that looks right but does not work (cardboard, clay, foam)	Checking size, shape, and how it feels in the hand
Scale model	A small, accurate copy, like an architect's house model	Showing a big design at a size you can hold
Prototype	A working model that looks and acts like the real thing	Testing whether it actually does the job

Computers add more: CAD (computer-aided design) draws a part so changes take minutes instead of days; a simulation tests a design on screen, like a virtual wind tunnel; a spreadsheet is a mathematical model that totals cost before you buy anything. Craft Lab is a model too: a place to try a layout and its joints before cutting a single stick.

Models before prototypes. Designers climb from cheap, fast models toward the real thing. A sketch costs minutes, a cardboard appearance model shows the shape, a Craft Lab build lets you try the layout and the joints, and a working prototype proves the idea before you cut good material.

Choosing fairly

Now narrow down. Constraints go first: any idea that breaks one is out, no debate. Then score what is left against the criteria with a decision matrix: list the ideas down the side, the criteria across the top, and rate each idea 1 to 3 on each criterion. Add across. The highest total is your best solution, and the low scores show every idea's weak spot before you build it.

A decision matrix. Three bottle-stand ideas scored one to three against three criteria. The scores are honest guesses, but adding them up turns an argument into a comparison, and the matrix shows where each idea is weak before you build it.

A matrix does not think for you. The scores are your honest judgment, and a trade-off is still a trade-off: the quickest idea may not be the sturdiest. But adding the numbers turns an argument into a comparison, and that is what step 4 needs.

Listing advantages and disadvantages for every idea is the same move in words. The matrix just makes the list easier to compare.

🔤 Words to know

Brainstorming

A group method for collecting many ideas quickly, with no judging until later.

Sketch

A fast, rough drawing used to get an idea out and compare it with others.

Rendering

A careful, realistic drawing with color and shading that shows how the finished thing will look.

Model

A version of an idea you can see and test before building the real thing.

Appearance model

A 3D model that looks like the product but does not work — for checking size and shape.

Scale model

A small, accurate copy of a big design, like an architect’s model of a house.

CAD

Computer-aided design — drawing and changing a design on a computer.

Simulation

A computer test of a design, like a virtual wind tunnel, done before anything is built.

Decision matrix

A table that scores each idea against each criterion so the totals can be compared.

Trade-off

Giving up some of one good thing to get more of another — quicker but less sturdy, for example.

🛠 Mini activity: Pick the winner

Run a brainstorm the right way, throw out ideas that break a constraint, then score the rest in a decision matrix and pick the bottle stand to build.

1
Here is what people said during the brainstorm. Sort each line: does it follow the rules or break them?
💡 Quantity, no judging, wild is welcome, build on others, write it all down.
For each card, tap the bin it belongs in.
"What if the stand hangs from the ceiling?"
"Only say an idea if you are sure it is good."
"Yes, and we could clip it to the desk edge instead."
"I’ll write every idea on the board."
"That would never work, be serious."
"Let’s just go with my first idea and stop."
Follows the rules
Breaks the rules
2
The constraints: cardboard and glue only, smaller than a lunchbox, done in two periods. Choose every idea that breaks a constraint and is OUT.
3
Tap the steps for using a decision matrix in order.
4
Scores (stays up / easy to grab / quick to build): Cardboard ring 3+2+3, Rubber-band cradle 2+3+1, Tall box with a hole 3+3+2. Which idea wins?

✅ Check: Brainstorm, Model, Choose

🔒

Finish the lesson first

Mini activity: every step needs its ✓.

The five-question check unlocks here as soon as the last one lands.

↑ Back to the activity

← Unit 4: Seven Resources of Technology Unit 6: Build, Test, Evaluate →

🎯

Unit 5 of 6 · about 22 min

Brainstorm, Model, Choose

Lots of ideas, cheap models, and a fair way to pick the best one

📖 Read 🔤 Words to know 🛠 Mini activity ✅ Check

Open up, then narrow down

Brainstorming

Brainstorming is a group way to collect ideas fast. The rules are simple and strict:

•Go for quantity. Twenty ideas beat three.

•No judging while ideas are coming. Not even a face.

•Wild ideas are welcome. A silly idea often has a sensible one hiding inside it.

•Build on each other. "Yes, and…" beats "but."

•One person writes everything down where everyone can see it.

Judging comes later, on purpose. When you are working alone, sketching does the same job: quick drawings on one page, no erasing, each one a different way to solve the problem.

Models: cheap ways to see an idea

You cannot compare ideas that exist only in someone's head. Models make ideas visible and testable before you spend real material.

Model	What it is	What it is good for
Sketch	A fast drawing, minutes, free	Getting ideas out and comparing them
Rendering	A careful, realistic drawing with color and shading	Showing what the final thing will look like
Appearance model	A 3D model that looks right but does not work (cardboard, clay, foam)	Checking size, shape, and how it feels in the hand
Scale model	A small, accurate copy, like an architect's house model	Showing a big design at a size you can hold
Prototype	A working model that looks and acts like the real thing	Testing whether it actually does the job

Choosing fairly

Listing advantages and disadvantages for every idea is the same move in words. The matrix just makes the list easier to compare.

🔤 Words to know

Brainstorming

A group method for collecting many ideas quickly, with no judging until later.

Sketch

A fast, rough drawing used to get an idea out and compare it with others.

Rendering

A careful, realistic drawing with color and shading that shows how the finished thing will look.

Model

A version of an idea you can see and test before building the real thing.

Appearance model

A 3D model that looks like the product but does not work — for checking size and shape.

Scale model

A small, accurate copy of a big design, like an architect’s model of a house.

CAD

Computer-aided design — drawing and changing a design on a computer.

Simulation

A computer test of a design, like a virtual wind tunnel, done before anything is built.

Decision matrix

A table that scores each idea against each criterion so the totals can be compared.

Trade-off

Giving up some of one good thing to get more of another — quicker but less sturdy, for example.

🛠 Mini activity: Pick the winner

Run a brainstorm the right way, throw out ideas that break a constraint, then score the rest in a decision matrix and pick the bottle stand to build.

1
Here is what people said during the brainstorm. Sort each line: does it follow the rules or break them?
💡 Quantity, no judging, wild is welcome, build on others, write it all down.
For each card, tap the bin it belongs in.
"What if the stand hangs from the ceiling?"
"Only say an idea if you are sure it is good."
"Yes, and we could clip it to the desk edge instead."
"I’ll write every idea on the board."
"That would never work, be serious."
"Let’s just go with my first idea and stop."
Follows the rules
Breaks the rules
2
The constraints: cardboard and glue only, smaller than a lunchbox, done in two periods. Choose every idea that breaks a constraint and is OUT.
3
Tap the steps for using a decision matrix in order.
4
Scores (stays up / easy to grab / quick to build): Cardboard ring 3+2+3, Rubber-band cradle 2+3+1, Tall box with a hole 3+3+2. Which idea wins?

✅ Check: Brainstorm, Model, Choose

🔒

Finish the lesson first

Mini activity: every step needs its ✓.

The five-question check unlocks here as soon as the last one lands.

↑ Back to the activity

← Unit 4: Seven Resources of Technology Unit 6: Build, Test, Evaluate →