I recently found myself needing to assemble a kegerator. For those who don’t know, a kegerator is a specially adapted fridge that can house beer kegs and dispenses beer from taps mounted on a font at the top. A carbon dioxide bottle keeps the system pressurised.
Regular readers might be aware of my travails successfully fixing a toilet and my subsequent anxiety that the whole thing might collapse in a shower of water and porcelain. I am not the handiest handyman but I compensate with a good dose of enthusiasm. Well, that’s until the cursing starts. So I was slightly daunted at the prospect of the kegerator, imagining a booklet full of incomprehensible steps to follow.
It was therefore a surprise to open the instructions and find them sparse. Instead, there was a list of links to Youtube videos. Which is where I encountered the kegerator guy.
I think he embodies a few key principles of teaching that mean that he takes his medium just about as far as it can go. Ideally, I would have liked to have been able to ask him a few questions, particularly because the kegerator I was working on was slightly different to his. Nevertheless, I was able to put the thing together relatively painlessly and with a fair amount of confidence.
If you watch the video – which is not recommended unless you have a kegerator to build – you will see that he always talks from a student’s perspective. He is not interested in showing how much he knows about kegerators – presumably, he’s designed a few. Instead, he is interested in explaining to us, in just the right amount of detail, what we need to do. And he makes careful use of non-examples.
Non-examples are usually missing from instruction booklets. A non-example is a description of what not to do and maybe why not to do it. For instance, the kegerator comes with beer ‘lines’. These are plastic tubes that carry the beer from a keg to a tap in the font and they are supplied about three metres long. I was tempted to shorten them, assuming that the extra length was provided in case you wanted to mount the taps some distance away from the fridge. The kegerator guy notes that a lot of people think this and go on to shorten the lines. But these tubes are not just for transport, they provide a carefully calculated amount of resistance to the flow of beer. If you shorten them then beer will come out of the taps too quickly and you’ll just have a load of froth.
So we are given an example of what not to do and a brief explanation of why. There is no deep discussion of fluid flow or anything else. We are told just enough to understand the reason for the long lines. Once we understand, we are less likely to make the mistake.
The kegerator guy continues like this. He seems to anticipate many of the questions we might ask, no doubt as a result of his experience with customers. He has lots of tips and further non-examples that show that he understands the difficulties that people will encounter.
I remember Kerry Hempenstall talking about the use of non-examples at researchED Melbourne and how Direct Instruction programs systematically introduce them. It seems like a pretty fundamental component of a good sequence of instruction. I think I have a new insight as to why.