Oisín Hurley's Weblog

old dog, new tricks

Archive for January 2012

CoderDojo Dublin

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There’s been some buzz about CoderDojo in the news recently. The CoderDojo was founded by James Whelton in 2011 to introduce kids to coding at an age when they are still in school, in an environment that supports learning. With support from Bill Liao, CoderDojos have sprung up in nine locations around Ireland.

This is relevant to my interests, and I wanted to see what the whole thing was about. To get in, you need a kid, so I brought the ten year old rugby fanatic that hangs around my house and eats the food. He chose the Programming Games with Python session – no doubt wanting to fulfill his dream of getting a decent rugby game on his iPod touch at some point.

Let me digress briefly on the subject of teaching kids how to manipulate computers with software code. We use physical tools to supplement our physical selves – pushing a nail into a piece of timber with your thumb is rarely successful. We need to use computational tools to supplement our own mental computing capabilities and allow us to enhance our reasoning processes. We are already equipped to pick up a hammer, see a nail and get a fair idea what to do next, but pick up an iPod Touch and put a rugby game on it? It’s not obvious how to get there, so instruction is required. And instruction needs to be imparted early, not because we want to make more developers, not because we want kids choosing a career in coding, but because we want to give them the tools they need in the 21st century to allow them to take advantage of every opportunity that comes their way.

Back to the dojo. Our host Eugene had his work cut out for him: 25 or more young humans, with vastly different capabilities in the area, short attention spans and different laptops all around. I decided take Mr. Rugby ahead with a copy of a simple Python text game involving choosing a cave and hoping the dragon therein doesn’t eat you, taken from the syllabus book.

The programming journey went like this – at each stage we thought of a goal and massaged the existing code and added new code to get to it. The kid did all the typing, saving, running, copying, pasting. I just pointed out now and then similar chunks of code that he could reuse and got him through any blocks.

  • I say – let’s extend the game from a choice between two caves, to a choice between three.
  • Kid says – let’s print out which cave was which at the end of the game, so you can see which was the right one.
  • We discover that strings and integers were different 🙂
  • We discover that when one chooses three random numbers in the range 1..3, there’s a good chance two will be the same, and it doesn’t make sense to have a bad dragon and a good dragon in the one cave – they are territorial.
  • Kid surprises me by coming up with a simple but effective way to make sure that the numbers wouldn’t clash, and we implement it – without using the modulo operator

Then we were done with where we wanted to go. Eugene was taking the kids along, helping each individually if he need to do so, and going down the same path initially, making an extra cave in the game.

But our local journey hadn’t finished after all. The kid had decided that now it was time to do some visuals and had sketched out a picture with three caves with numbers over them. Here’s where having a software savvy dad and the internet is a win: we grabbed a free pixel art program, muddled out how to use it, and while he drew the screen, I frantically researched free Python game libraries.

Aside – before we got onto the visuals, I spotted a few areas in the code to put in a couple of for loops, and suggested we ‘tidy up’ the code a bit so that I could show these and explain them. Why? was the response, the thing worked didn’t it? The important thing at this point is to shrug and agree – the lad is not a professional coder, he doesn’t need to refactor, he just needs results. In fact the whole thing needs to be results-driven. This is why you use a tool – not because it’s lovely or elegant or makes you feel special, but because you have a job to sort out. Then you put the tool down. It’s only when you get trained in how tools work can you start making your own tools. cf. lightsabre etc

Eventually I stumbled over pygame, which turned out to be just the tool we needed. We made a plan to write a small programme to try it out, and there was palpable excitement when our extremely amateurish drawing of caves popped up, surmounted by a hand-scrawled Danger!! sign.

Screenshot of game

On the way home on the train, we designed an rugby-themed 8-bit scroller for the iPod Touch and set up the kid’s github account. When we arrived home the kid insisted, with uncharacteristic determination, that we finish the Dragon game – adding keyboard control, putting in dragon graphics, conveying the result visually. Next challenge: the rugby game. Yikes!

Very little of this article has been on the details of the CoderDojo, but you may have already realized how the CoderDojo was instrumental in making this tiny but important success work. It provided us (and I write ‘us’ deliberately) a place in which learning was the norm; it provided a place where myself and himself were on the same team working towards an external goal; it provided a place that wasn’t dominated by adults. And that last one is the key one I think.

Many thanks to Eugene and the team behind CoderDojo Dublin for their commitment and patience in putting the series together, they are providing an really valuable service, on their own time.

Written by oisinhurley

January 22, 2012 at 3:29 pm