Who knew there were so many weak definitions of “series circuit”?

Series circuits are one of the foundational concepts in electrical work, and one of the first things students build/think about/get assessed on in their first months at school.  My definition of two series components:

  • Two components are in series if all the current in one flows into the second, and all the current in the second comes from the first

Things I have heard about series components:

  1. Components are in series if they’re in a square shape
  2. Components are in series if all the current in one flows into the second
  3. Components are in series if they’re both connected to the power supply
  4. Components are in series if they’re aligned in a straight line

In the first year of the program, we spend a lot of time refining our ideas about which circuits have which behaviours.  We refine and revise and throw out ideas.  By the end of December we should have something fairly strong.

Last week, I had a second-year student tell me he knew that two components were in series because of reason #3 above.  I’m struggling to make sense of this, and the accountability of teaching in a trade school hangs over my head like the razor-edged pendulum in the pit.  In May, some of these students will be working on large-scale industrial robots.  These things weigh tons, carry blades and torches, and can maim or kill people in an instant.  Electronics is not an apprenticeable trade. Grads will not carry tools for a journeyman for three years — they get put right to work.  Also, electronics is not a construction trade — it is a repair trade.  That means that work is almost always done under pressure of short timelines and lost money — the electronics tech doesn’t get called out until something is broken.

I have two years to make sure they are ready to at least begin their industry-specific training.  It’s not good enough for them to sometimes make sense of things — they need nail these foundational concepts every time in order to to use the training the employer provides and make good judgement calls on the job.  Please, no comments about how education is about broadening the mind and this student is learning lots of other valuable skills.  While that’s true, it’s not currently the point. When that electronics tech does some repairs on the heart-rate monitor keeping tabs on your unborn child, you are not going to be any more interested in the tech’s broad mind than I am.

What does it mean if a student can spend 4 months in DC circuits, not fully integrate the concept of series components, pass the course, and 8 months later still have an unstable concept?

Here are all the ideas I can think of at the moment.  Don’t panic — I don’t think these are all equally likely.

  1. Their experience in DC circuits is not doing enough to help them make sense of this idea
  2. The assessments in DC circuits are not rigourous enough to catch students who are still unsure about this
  3. This student is incapable of consistently making sense of this idea, and should not have been accepted into the program in the first place
  4. It’s normal for students to form, unform, and reform their ideas about new concepts.  It’s inevitable, and sometimes students will revert to previous ways of thinking even after the fantastic course and the rigourous assessments.

If it’s #1, I’m not sure what to do.  I’ve already given over my courses to sense-making, critical thinking, and inquiring.  Do they need more class hours, more time outside class hours, or just different kinds of practice?  Maybe the practice problems are too consistent, failing to address students’ misconceptions.

If it’s #2, I’m not sure what to do.  I feel pretty confident that I’m assessing their reasoning rather than their regurgitating.  More assessments might help — not sure where to get the time.  A final exam might help.  I can’t see my way clear to passing or failing someone on the strength of a final exam, but I’d at least know a bit more about which concepts are still shaky.  I’ve sometimes given a review paper in January on the concepts learned in the previous semester, and worked through multiple drafts — I could start doing that again.

If it’s #3, I’m definitely not sure what to do.

If it’s #4, how do I reconcile this with my sense of personal responsibility to not send them out to get injured or injure someone else?  I realize I’ve framed this in a fairly dramatic way, and not every student who’s unsure of what a series circuit is will end up harming someone.  It’s much more likely that they’ll end up on the job and start to consolidate their knowledge and clear up their misconceptions.  However, it’s also likely that they’ll end up on a job where they suddenly realize that they don’t understand the basic things they’re being asked to do.  This bodes poorly for the grad’s confidence and enjoyment of their career, the employer’s willingness to hire future grads, and of course the quality of our biomedical equipment, manufacturing equipment, navigational equipment, power generation instrumentation, … .  It also bodes poorly for my ability to believe that I am doing a reasonable job.



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