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Mind Tools

I occasionally feel a little guilty. Although I am very much committed to the idea that technology should be integrated, no, more than that, embedded, into what happens in a classroom on a day-to-day basis, the truth is that I have spent many years teaching computing as a discipline in its own right. And I have to keep telling myself that that’s ok, that there are still many kids who have a deep interest in technology for the sake of technology and find the very nature of computing highly engaging as a stand alone topic. So I’m cool with that. It’s ok to be a geek.

I believe one mark of a good teacher is to be able to take complex ideas and simplify them without making them simple. For example, there are a couple of concepts in the realm of computing that are not really all that hard to understand but can be very hard to explain. Binary numbers can be one. Vector graphics another.

vectormagic.jpgSo I was really impressed when I saw VectorMagic, a somewhat geeky (yet very cool) web app put together by James Diebel and Jacob Norda from the Stanford University Artificial Intelligence Laboratory. I blogged a couple of thoughts about EPS files and vector graphics the other day and in the comments I was pointed to VectorMagic by Kathy Nann. What an amazing tool! Thanks Kathy!

I won’t blather on about the need for vector graphics and when you should use them… I blathered enough about that in that other post, so go read that if you dare.

What VectorMagic does is to take a bitmapped image (jpg, gif, bmp, etc) and trace the shapes contained within them in order to to convert them into vector outlines. This gives a remarkable crispness to the image at any resolution. Vector images don’t get blocky and full of artifacts as they get bigger. They just recalculate how to draw that shape a bit bigger using a nice sharp edge. I’m so glad I found this tool and I know I will get lots of use out of it. (Well, maybe not lots, but just knowing its there and what it can do makes it all worth it.

But the other thing that really struck me is just how good this sort of application is as a teaching tool. Because of the way it steps through the process and how it asks the user for questions about the image, it makes it so much clearer as to the real differences between bitmap and vector graphics. It even places them next to each other at the end, and lets you zoom and pan in real time to inspect the two image types. Visually, this is a really powerful way to learn about a concept that can be otherwise quite nebulous and hard to explain, and after using Vector Magic to convert a few images it would be hard NOT to understand the difference.

And it got me thinking about just how much we can use the the intuitive and malleable nature of software to assist us in explaining and investigating tricky ideas. Programs like VectorMagic are amazing in the way they can be used to visually demonstrate the bitmap/vector concept. Trying to explain sound waves to junior students can be hard, but when theses students can create, see and manipulate waveforms directly using Audacity it makes it much more concrete. Playing whatif games with spreadsheets, tracking data visually using Gapminder, directly manipulating the globe with Google Earth or creating 3D models with SketchUp… these tools make it almost trivial to convey what used to be challenging and hard-to-grasp ideas.

All of this should pave the way for us to help kids come up with better questions, and make better use of this new information. I’m going to try harder to make these tools do the jobs that they are good at, so that I can spend more quality time working with kids on the thinking skills that really matter.

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iTunes is your friend

I really like iTunes. It’s a wonderful piece of software that just works as expected and does it’s job really well.

I’ve been asked to talk at the PowerUp conference on the Gold Coast this weekend and was given an open opportunity to talk about whatever I wanted. Although I think the Web 2.0 story is the one most people still need to hear, the general feeling was that there were already plenty of people talking about web 2.0 stuff, so something a bit different would be good. (Besides, my other session will be about web 2.0 stuff anyway, looking at tools for collaboration)

I’m a bit wary of being caught out without Internet access when I present… I’ve been in situations before where I was told there would be access, where there was access, where I should have been able to get access, but for whatever reason the firewall gods were not smiling upon me and I had none. I don’t expect that to be the case this weekend, and of course I plan to present it live… but I’m starting to learn to cover my bases and to that end I’ve been making a few screencasts using iShowU, capturing those portions of my presentations that require access to the cloud. Just in case.

So if you’re interested, here is part of my presentation about iTunes. I thought this stuff was kind of obvious but I’ve spoken to many people lately who still haven’t got their head around this stuff.

[kml_flashembed movie="http://www.youtube.com/v/00viJjSQL_Q" width="425" height="350" wmode="transparent" /]

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Audio Plumbing

picture-1.pngI’ve been trying to make a screencast of Skype conversation. And I thought it would be pretty simple. But as so often happens, there are technical issues to overcome that can make things so much trickier than you first thought they would be.

I’ve done quite a bit of screen capturing before, usually for short training videos on how to do certain software tasks. In fact I made a CD for a commercial training organisation a few years back that had over 80 tutorial screencasts on it made with Capture Cam Pro, so I figured I knew how to do this stuff. I’ve also been using Jing lately to make short screencasts on tech tips for our school network users. I think that screencasting is a great way to learn (and teach) this sort of practical, “show me” sort of stuff. Atomic Learning is another excellent resource based on this idea.

So I wanted to make a couple of screencasts to demonstrate how to use the features of Skype. I’d been using Snapz Pro X on the Mac, but wasn’t totally happy with it. I’d heard good things about iShowU so I downloaded a copy to try. I only had to use it a couple of times before I realised that it was going to be well worth the $20 they were asking for it, so bought a copy immediately. Easy to use, lots of professional options, and very customisable. A cool tool.

So I set up a screen capture, fired up Skype and called the Skype call testing service at echo123. iShowU captured all the on-screen action easily, as well as my microphone input, BUT not the audio coming out of Skype. Hmmm, that’s no good… I can’t do a demo of Skype if I can’t hear the conversation played back in the screen capture. I thought of a bunch of ideas to solve this, including using Audio Hijack Pro to capture the Skype audio, iShowU to capture everything else, and then dropping it into iMovie to edit them into a single movie but that seemed like it was all getting too hard and time consuming. I’m basically quite lazy, so I wanted a better, more elegant solution.

After quite a bit of trial and error I finally figured out how to do this, so here is my solution in case you ever need to do it yourself.

picture-2.pngThe trick is to use Soundflower, a Mac system extension that lets you route audio around the system in non-standard ways. From the Soundflower website, it says “Soundflower is a Mac OS X system extension that allows applications to pass audio to other applications. Soundflower is easy to use, it simply presents itself as an audio device, allowing any audio application to send and receive audio with no other support needed. Soundflower is free, open-source, and runs on Mac Intel and PPC computers.”

So, here’s how you do it – or at least it’s what eventually worked for me after much trial and error…

  1. First, I set the audio inputs of the Mac to Soundflower (2ch), that’s input, output and system.
  2. Then in the Skype preferences, set the Audio input to your desired microphone (I used a USB headset mic) and the Audio output to Soundflower (2ch). I set the ringing to Soundflower as well, but that’s probably not so important.
  3. picture-3.pngFinally, in iShowU, set the Input selection to Record Microphone Audio, Force it to Mono, and turn on Record System Audio. Set the microphone input to the USB headset (in my case). I also prefer to get the monitor feed while both previewing and recording, so turn that on if you want.
  4. By the way, setting the compression to H.264 makes a huge difference to the size of the final files.

There you have it. From what I can figure out, it works by routing the Skype microphone input to Soundflower, then routing its output to be the Mac’s regular audio input as a Soundflower stream. Then the Mac uses that diverted audio stream and treats it as the regular mic input to the computer (except after passing it via Skype it now has the entire Skype conversation in it) and then using iShowU to monitor the standard audio feed, which now contains the Skype audio. This may all be totally useless information to most of you, but for someone out there it may just save you a whole lot of time. I hope so.

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