Yum: Vector-Based Popcorn

Working with vector graphics is a little like working with clay.  You start with flexible lumps of "stuff" (rectangles and ellipses), then push, pull, bend, and layer until you have something.  I made the graphic below and an accompanying Scratch project to illustrate that basic idea. I plan to pass it out to my classes on Tuesday. 


The four panels of the popcorn bag, and the two bits of red stripe each began their lives as rectangles.  Gradients were added to the fill, and points were added to the paths.  Points were pushed and pulled here and there.  The kernels were made with ellipses.  They all come together to give the illusion of a bag of popcorn.  I hope you find this useful!  I made it my design goal to use no words - I wonder what adding some would do?

Lo-Fi Cut-Out Scratch Blocks


In class, I sometimes use some faux Scratch blocks I have cut out from foam board.  The foam has worn over the months, so I thought I'd make a fresh batch - maybe smaller sets printed on card-stock?  I am thinking it would be good to do some more gross-motor code-it-on-the-floor stuff.  One thing that is fun is to have one kid be the sprite and another pair assemble scripts - and the sprite kid acts it out.    The class gets to "evaluate" and see if the Sprite was following the directions.  Another thought would be to glue this on thicker-still-foamy stuff, and cut those out.  Or blow it up and use it as a template to cut out the big ones.  Who knows? If you like, you can download a PDF of these lo-fi blocks by clicking here:  Download PDF

Starfish in a Hot Air Balloon

Here is a concept kit I made in Scratch to teach the use of conditionals with a loop and operator.  Here is a link to the puzzle, and here is a link to the solution


Starfish, naturally, would like to fly his hot air balloon.  As the programmer, your job is to create scripts that

   1. Make gravity slowly pull the balloon down until it hits the ground.  Since Starfish is in a balloon, we can forget acceleration. 

   2. Make the balloon go up if Starfish turns on the gas (spacebar), and then fall again if he lets go.  

   3. Show the Starfish's response to the action.  

This project went through a number of iterations.  I had some versions with all kinds of variables to calculate acceleration and create states for the Starfish, but I kept seeing if I could make things simpler.




Concept Kits in Scratch

I have been experimenting with various formats for introducing concepts and skills in Scratch for my 3-6th grade classes.  In particular,  I have been working on ways to engage those kids who have a harder time "getting it" early on.    

I have created a few projects that I'm calling "kits."  They have simple goals, and some scaffolds built in (e.g. pre-dragged-out blocks).   They are somewhere between a Scratch card and a blank slate.   Today I took the same basic concept from 1.4 "forever-if" and used it to make a 2.0 version: "Conditional Kit #1

Slides for Teaching "Forever If" in Scratch

Here is a slide show I made to explain the big idea behind "forever if" in Scratch 1.4.  My goal was to make a project that would illustrate these ideas with as little code as possible, as I had a number of students frustrated by this.   All the necessary bits can be seen on the last slide, which I kept up for the working period.  If you are on 2.0, the forever and if blocks are separate.  The keynote file has animations...(download)

Sound advice

Wise words

Wise words

I wish that my teachers growing up had more often told me to "Mess around" and "guess."

I took this photo at Scratch Day 2013 at MIT.  It was posted on a wall where participants were asked to write down what they did when they got stuck in Scratch.   If you are the kid who wrote this, thank you. 

 As both a student and teacher, I have noticed that willingness to follow the advice given above is often directly correlated with success in programming.  I find that once students are over the feeling that they have to get it right the first time, they start to experiment and "mess around" until they discover both the "answer" and the logic behind it.  

Marble Mazes and Programming

Marble mazes are a staple in the world of constructive play.  For reasons that I'm guessing are as deep in the genome as the reasons we like rhythms, melodies, and Angry Birds,  we like to watch a ball bounce down some sort of landscape, watching how the laws of physics play with our creation.  But why? Here are my conjectures.

1. It is a way to experiment with and understand our most constant frenemy,  gravity.  Just how much can we alter the path of a falling object before it ends up where it is going to end up (at least for the observable present).  Just how much do the angles and materials and sizes of things matter?  Is falling inevitable? How much up can we get out of some down? 


This marble maze is in the Holyoke Children's Museum, in Holyoke, Massachusetts.

This marble maze is in the Holyoke Children's Museum, in Holyoke, Massachusetts.

I also see a lot of parallels between building a marble maze and programming.   If we are engineering a bit of software with a particular goal in mind, then we devise a set of instructions within the limits of a code, and see if we can get the result we are looking for. (E.g. I want to make the ball jump and then land and keep rolling)  If we are tinkering with programming we play with different sets of instructions, and our observations of the results help us to discover and gain fluency with the logic of the language.   We watch the ball bounce, roll, accelerate and decelerate and it teaches us about the structure of the physical world and the rules it sticks to.  

If we have a certain outcome in mind, and it doesn't work, we engage in the debugging process - finding the unknown mistake in our logic that is preventing things from ending up as we'd hoped.  E.g. "Oh, it doesn't make it over the gap unless it is going fast enough...it doesn't go fast enough unless it is rolling for a few seconds in one direction...if I want it to roll in that direction, I will need to place more pieces here...no here.  Ok that worked!" 

Computers in Pretend-Play

The "compooter"

The "compooter"

A few months ago, (likely as a result of seeing her parents nearly constantly pecking away at their laptops) our daughter started to pretend to be on the computer herself. She created this here computer.  So, some thoughts (Besides the "awwwww", which I do say when I see it) :

 1. We already know that kids develop competencies with real life skills through play that imitates what they see adults doing all day.    So, score one more for developmental psychology and the value of play.  I would be interested to find out if there is recent research on how computing shows up in pretend play. I know, lmgtfy. 

2. It's interesting to imagine what letters look like to four year olds.  They have a clear pattern - a letterness - but they are not quite known yet.  I guess it's how Greek looks to me - "I kinda know that letter is a whatsit called, looks like A but does it say L or something? And that one, whoa what does that one do, I don't know..." 

3. It's a nice balance of chaos and order - a.k.a. creativity?


Direct Instruction, ok I said it.

That sums up the debate I go through just about every day as an educator.   Despite a whole lot of progressive training and thinking, I too sometimes wish "they would just get it so we can keep going..." 

For some kids,  just seeing the first two scratch blocks connect and the cat move as a result of a space-bar press is enough send them off and clicking, experimenting and watching results, picking up understandings on the fly.   For many others, I've reluctantly found that more direct instruction at the get-go has helped them get engaged sooner. 

Thinking about this after class last year, I wondered: "What criteria should I use to decide when to offer a student 'direct instruction'?  What do I even mean by that term?

At first, there seemed to be an obvious answer: "When the student is asking for help, answer their specific question."   When students feel confident and curious enough to ask a question, they make our job easy and gratifying.  They ask a dream question like: "How do I get him to move in the other direction?"

But it turns out these are often exactly the students who really don't need the direct instruction.  They ask, and we get to respond like the teacher from a book we read in grad school: "Well, take a look at how you made him go to the right. What are those blocks saying? What do you think?"  Then they get back to puzzling and we move on. Yay.  I didn't have to do any direct instruction after all. 

I think it gets complicated when students are in a far more hazy, and less happy/engaged zone, and they are asking something that indicates we might just be about to lose their interest,  something like, "Wait, so what is the cat supposed to do..."?

If I answer, "It's not supposed to do anything, you get to invent something for it to do!" I may get a smile and observe a renewed sense of confidence, but I will just as likely get a look of disbelief and see the student slump down a notch.  The thought bubble pop up: "I really don't get this."

These are the moments, I think, to decide on a kind of direct instruction where we go from "teacher" to "pushy experience-sharing person."  I might say something like, "Here's something I think is cool, can I show you what I was thinking when I was trying to figure it out?"