Dealing With Student Misconceptions

I was reading through The Big Book of Computing Pedagogy, as one does, the other night. Specifically, the section on student misconceptions. Misconceptions are one of my favorite topics in teaching computer science. The articles in this book are very helpful in understanding what student misbelieve and why they do so.

I’ve seen students with all of the common misconceptions and, of course, I try my best to help them overcome them before they get students into trouble.I tried to remember if I experienced any of them myself but memory of 50 years ago is very selective. What I do remember is that I had some experiences of getting very close to the hardware early on. While my first course was learning FORTRAN the computer we used required some extra (compared to today) to run. Specifically, it requires that one toggle in some instruction in binary using toggle switches to get it to read in a couple of punch cards that did the next phase of the boot up.

Not long after I learned the first two of what would be 7 or 8 assembly languages over my career. There is something about toggling a memory address so that one could read (in binary lights) or enter information in binary with those same switches to program a computer that give one a good understanding of what memory actually is.t

Those days are long gone of course and while assembly language still gets one close to the computer and gives an understanding of how things like memory work it can also be a gate or barrier to students. It’s actually not the ideal way to understand concepts that one might think. It’s not the sort of visual experience that today’s students are used to learning from.

What we really need is some better visualization tools for introducing concepts. My first thought was using debugging tools such as those built into tools like Visual Studio. One can single step though instructions and view the contents of memory (variable) locations. It works but it is slow and tedious. That may be fine for debugging but for learning it has a high cognitive load that gets in the way of what we’re trying to do in teaching.

So I have been thinking about how to create visualizations that are simple to use and that might help clear up misconceptions. Two things my thinking is focusing on are how variables and memory work and how loops and loop control variables work. Eventually I have to narrow it down to one of them to start. I should probably look at what might already be available first. I thought I would start by asking you, my readers, for suggestions. So, any ideas? How do you help students visualize these concepts? Any suggestions on tools for creating visualizations?