Mylène has some interesting musings in her post Who knew there were so many weak definitions of “series circuit”?
This is the sort of misunderstanding that is hard to discover with clicker questions or multiple-guess tests. Even standard design questions might not reveal it.
I think that there is a way to uncover (and maybe correct) this sort of misunderstanding in a peer-instruction context, and I think I might try it in the applied circuits course (assuming I get to teach it). During the first week, I’d draw schematics of resistors connected in series and in parallel on the board, and ask the class to identify which one is series and which parallel, just with voice response. I expect that essentially everyone would get that right. Then I’d pass out index cards and ask everyone to write a definition of a series circuit on one side of the card, without discussion. After a couple of minutes, I’d have them compare definitions with a couple of neighbors, discuss for a couple of minutes any differences in definitions, then write a revised definition on the other side of the card. I’d then collect the cards, draw a few at random, and discuss the (revised) definitions with the whole class.
I’ve never used that approach to instruction before, but it seems to be a good one for checking fundamental concepts, but only if there is a high probability that students will get it wrong on the first attempt. I’ll have to look for opportunities to use it in my bioinformatics class this quarter.