Visual Programming Via The Squeak Car Demo

Dan GrossmanUniversity of Washington

CS4HSAugust 6-8, 2009

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This 120 minutes

• 20 minutes: – introduction – “cooking-show demo”

• 50 minutes: paired up in the lab “trying it out”

• 50 minutes: – recap concepts– a demo I made in 10 minutes– brainstorm

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“Visual programming”

• “Virtual worlds” for scripting, simulation, animation, building control systems, etc.– “Discovering” core math, science, and computer

science with some “computer game” feel

• Popular ones with amazing stuff: – Squeak Etoys, Scratch, Alice

• Today: A demo for 11-year-olds– The point is the idea & approach– Not the specific content

• (make up own or search web later)

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Why?

• Virtual scriptable worlds compared to real-world– Easier to control– Faster– Cheaper– As a result: More fun

• Computational concepts without a CS class– Scripting– Modeling– Simulation– Feedback and control loops– Conditionals– (plus tons of useful math, probability, statistics, …)

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Why me?

• Computer science faculty since 2003– Programming languages

(ways to think about computation)– Believe “computational thinking” is essential for all

college-prep high-school students• Not the same as programming class• I never programmed until college

– But I’m not a high-school teacher• Show you Squeak; hope you think it’s useful

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Cooking-show

• 4x-speed version of what you’ll do in the lab– Feel free to play around also, but try to get through

most of this– Step-by-step instructions in lab, so just “get a

sense” here

• By the way, I’m new to Squeak – you pick it up fast

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Outline

1. Paint a car; keep it

2. Use mouse and object viewer to move car

3. Skip saving/loading projects

4. Script circles/polygons (pen down)

5. Steering wheel connected to car

6. “Robot” car that follows the road

7. Car with random speed

8. (Time permitting, car that accelerates at each step)

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Let’s go try it ourselves!!!

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This 120 minutes

• 20 minutes: – introduction – “cooking-show demo”

• 50 minutes: paired up in the lab “trying it out”

• 50 minutes: – recap concepts– a demo I made in 10 minutes– brainstorm

10

Outline

1. Paint a car; keep it

2. Use mouse and object viewer to move car

3. Skip saving/loading projects

4. Script circles/polygons (pen down)

5. Steering wheel connected to car

6. “Robot” car that follows the road

7. Car with random speed

8. (Time permitting, car that accelerates, at each step)

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A ton of CS in there

• Using mouse and object viewer to move car– State of a model– Multiple representations for viewing and controlling

the model

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A ton of CS in there

• Script circles/polygons– Expressing repetitive tasks via an algorithm– Automating repetitive tasks– Approximations, derivatives, limits

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A ton of CS in there

• Steering wheel– “Wires” for connecting outputs to inputs– Perspective and relative positions

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A ton of CS in there

• Smart car– Feedback and control systems– Conditionals

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A ton of CS in there

• Random speed– Simulation of a random process for collecting

statistics• A key alternative to mathematical analysis• So much faster than rolling real-world dice• Let me show you my “roulette car”…

– In theory, analysis is more convincing– In practice, many people learn visually

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Why?

• Virtual scriptable worlds compared to real-world– Easier to control– Faster– Cheaper– More fun

• Computational concepts without a CS class– Scripting– Modeling– Simulation– Feedback– Conditionals– (plus tons of useful math, probability, statistics, …)

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Much, much more available

• Plenty of online information, forums, etc.

• Squeak Etoys school projects: – http://squeakland.org (not squeak.org)– Slightly newer version than we had in the lab– Try Showcase, then Showcase by Age

• Actually, instead try out:– Scratch: http://scratch.mit.edu/– Alice: http://www.alice.org/– (what? and start over after 2 hours?? )

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So…

What in your courses could use something like this?