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Low Level CS in HS

There's been discussion recently about current CS student's knowledge, or lack thereof of hardware. The discussion was spurred when this article made it's round in the CS Ed communities. My friend and fellow CS Ed Blogger Alfred Thompson gave his take on his blog. I thought I'd share mine here.

First, let's get some definitions straight. The original article wasn't really talking about hardware. The author was really talking about what I'd call "low level" computer and programming concepts. Things like bit level operations, the internals of memory management and in fact memory management altogether, and things like interrupts and how system calls work.

When we're talking hardware, we could be talking about a couple of things. It could be Information Technology (IT) hardware - putting together computers. Knowing interface standards like EIDE or the older SCSI. Networking technologies. We could also be talking about things that should be covered in robotics - wiring and programming an ATMEL, the processor under the hood on an arduino directly to control a device for example. Robotics, however, at the K12 level is usually more of an intro programming class with physical output instead of merely visual on a screen.

The question that arose was this: should any of these be covered in K12?

Let's look at each in turn.

IT Hardware? Probably not, at least not across the board in all CS classes. Building computers and wiring your own networks were big in the 90s and turn of the century. Not so much anymore. You used to be able to purchase components at a variety of places but now, vendors have dwindled. At the same time, the market has consolidated and moved more towards laptops or smaller - platforms students can't easily work on. On the other hand, this can be and should be a fun and great elective.

Low level robotics type hardware? Also, not in required classes but would be a great elective.

That brings us to the low level programming concepts. Once again, as an elective this can be great. In addition to covering some of this in the classes I designed at Stuy, I created and offered a System Level programming class that covered a lot of this. It was popular among the CS students and from what I was told, super worthwhile for those who went on to study CS or a related field in college.

What about for everyone else?

That's the question. On the one hand, time is very limited. If a school offers or requires CS it might just be one semester or one year. You can't cover everything in that amount of time. Also, as Alfred pointed out in his post, we don't currently even have nearly enough knowledgable K12 CS teachers to teach the basics.

I'd like to try to make a case though for including some of it.

Even though everyone uses computers these days, they can certainly be intimidating and feel like magic. People have no idea how they work. I joke with my students that if they unplug the keyboard quickly while typing they can shake some characters out of the cable. Teaching some low level CS concepts can demystify computers. Take away the fear. Just as learning some programming and algorithms can demystify the "magic" of recommendation systems and high level wonders, some low level knowledge can demytify how these computer things work inthe first place.

I'm not talking about going all Nand to Tetris. I'm also not talking about dropping in topics out of context. The College Board did this famously with binary, decimal, and hex. Without context it's meaningless and worthless. Hunter, where I last taught did the same thing. They required binary, decimal, and hex in their CS0 course. I ignored it. The argument the professors gave was that the kids needed it when they took their first systems/architecture course. I asked them, "well, for all the students in all the other CS0 classes, they did cover the topic, did it really help?" The answer was "no, they all forgot and we had to reteach it." So much for it being important in CS0.

I'm talking about a unit where you can get far enough to understand something memorable. I brought a bunch of HS students to a 45 minute talk once explaining how solid state memory worked. These kids had zero background and the speaker kept things at an informal level but after the 45 minutes, those kids understood at a basic level, how a flash drive stored information.

Another example is a unit developed for my intro course. The heavy lifting was done by a colleague and friend of mine - I can't take the credit. The unit centered around a small assembly interpreter that he designed and built a web emulator for. Kids learned some logic gates, how you could do arithmetic and were also able to see how memory worked. The kids got to look behind the curtain. Sure, their laptop was a bazillion times more complicated but at their cores the same things were happening.

Now, the rub comes with resources and bang for your buck. Can you spend a couple of week on something like that? Do you have teachers who know enough to do it? If you do it, what other topic(s) can't you cover.

If you've only got one semester with the kids, you've got to call your shots. I can't say that low level CS is the most important thing to cover there but when there is time, I think it's certainly worthwhile. On the other hand, if you have a year or more with your students, I'm pretty sure a creative teacher can come up with a way to get the basics in.

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