This year, the first-year class has created their own model of what electrons do in circuits.  We add ideas to the model by investigating questions that they are interested in.  The questions have included everything from “If I had added another resistor to the circuit, would that have prevented my component from smoking” to “Do electrons always travel at the speed of light?”  There are two main ways that ideas get added to the model: research or measurement.


Students individually choose a question from our “question bank,” which I collect based on their comments. They research the question and evaluate the quality of the reasoning in the sources.  They present their findings to the class; the class then assesses the research and decides whether to accept it, reject it, or send it back for clarification.


I choose some questions from the question bank that we have the equipment to take measurements about — usually questions that have come up in the past week.  For a 3-hour lab period, I typically pick 4-6 questions. Everyone takes one measurement for each question.  A question would be something like “What determines the voltage across each component: position, resistance, other?”  The questions are specific enough that they suggest a certain circuit arrangement, but students are free to choose component types and values, voltage sources, etc.  Students must keep records of their circuits and measurements; I cam-scan their records at the end of the day.  The following day, we break into 4-6 small groups (as many as there were questions).  Each group collates the measurements for their assigned questions, looks for patterns, and recommends ideas to be added to the model.

Motivating the Model

I explained that we were building the model we’d be using to predict the behaviour of circuits for the  next two years, and that on tests, I would be evaluating whether they used their model in a well-reasoned way (“You’re going to grade us based on what we say??”  They were astounded).  I cautioned them against rejecting things too quickly, since they would need as much structure as they could get.  I also cautioned them against accepting things too quickly.  If they accepted something that was contradictory or unclear, they would have to spend extra time down the road rooting it out, and rooting out any other ideas that had been accepted based on the poorly-reasoned one.

Results: Concentration, Community, and Discernment

We started the year with research presentations, since students’ early questions weren’t testable with the lab equipment we had.  Everyone had to give a short (3-min or less) verbal presentation of an idea that could be added to the model.  When they were not presenting, students completed a “Rubric for Assessing Reasoning” (see the comprehension constructor shown in this post).  There were 12 students in the class.  At the end of the presentations, each student turned in 11 rubrics.  Well holy smoke, you’ve never heard a quieter bunch of 1st-year students.  They were listening so hard you could hear a pin drop.  They shushed each other and asked the speaker to repeat things when they weren’t sure of the exact wording.  They were writing like mad.

After each presentation, we discuss it and voted on it.  For voting, they used the feedback flashcards I’d made in September.  Green means accept; red means reject; yellow means “I have a question or want something clarified”.  Consensus is required for an idea to be added to the model.  In that first week, I contributed a lot to the discussions — asking questions, pointing out possible conflicts.  Now, the students do most of that.  (Those conversations have yielded several astonishing innovations, including class training on basic facilitation techniques, a formal mechanism for figuring out who has the floor, and a demand that we sit in a circle.  I am not making this up.)

That was the beginning of our model of atomic structure and electricity.  The students have become adept at differentiating between questions that must be answered before we accept an idea, and questions that are not stopping us from accepting the presentation (those end up in the question bank, of course).