Eliciting student ideas (Blogging from the AAPT)

by Stephanie Chasteen on July 26, 2009

Today’s session is all about using diagnosis, or assessment, in your teaching (“Designing a Diagnostic Learning Environment in the Pre-College Classroom:; Lezlie DeWater, Eleanor Close, and Hunter Close).

Formative assessment is assessment that happens before or during your teaching, to help students learn.  Summative assessment is what we more typically think of as assessment — testing your students at the end of the lesson or instruction.  So, you could say that formative assessment is “are they getting it?” (and then using that information to help learning) and summative assessment is “did they get it?”.

Formative assessment, then, is

  • Before or during learning
  • Not judgmental (eg., not grades, though we can tell students if they’re not getting it right)
  • Focuses on student thinking and learning
  • Helps students learn
  • Opens a two-way dialogue between students and teachers (“what is making sense or not?”)

Here is the first step in using formative assessment in the classroom.

1.  Elicitation activity

A puzzle or quandry to get students thinking, and bring out their existing ideas.  This helps you start where students are.  In this workshop, they showed us a short movie about energy and asked us to write down some ideas that the movie brought to the fore.

Here’s the movie:

For example, some ideas this brought up for me are:

  • The springs of that trampoline must be very strong because the energy of the elephant as it comes down is very large (high mass, high velocity), and the springs translate all that KE into PE and then back to KE
  • The elephant sometimes put energy into the jump (with its legs) and sometimes not (as when it hit it on its back) — and we saw it going higher as he jumped.  We also couldn’t see what happened at the bottom of the jump — was he pushing?  It was so quick, it seemed like he turned around almost too quickly from an impulse/force point of view.
  • The elephant was probably tired when he was done — the conversion of biological energy to mechanical energy.  All the energy for this came from what the elephant ate for lunch.  He should have broken a sweat to put out that much energy.
  • The lost energy, of course, all goes away as heat!  And we didn’t see what happened between the high bounce and when the elephant is walking away.  It must have slowed down.  That energy had to “go somewhere.”
  • We see translational, rotational, and elastic potential energy in this video.

What could kids get out of such a video?

  • How can we get students to have a real discussion about energy, instead of focusing on what happened in the movie?
  • It could bring out some of their naive ideas… but they’ll talk about a lot of off topic stuff.  Is it better to ask them to focus on energy and try to force that conversation, or is it better to get them to throw out all their ideas about the video, and converge on energy from those ideas?  Their ideas are valid and interesting, take those initial ideas and grow them towards what you want them to be focused on.
  • We could show the video more than once and see what changes about their observations.
  • Kids will remember this, it’s engaging, they’ll be involved, it’s funny.  And there’s no right answer, unlike Just In Time Teaching.  It’s not a textbook problem where they’re focused on getting the right answer.

They’ve used this video as an elicitation activity for pre-service teachers, before instruction about energy.  About 2/3 of the group said that they didn’t know what to say, other than “kinetic energy.”  They felt that they had to write down things that sound “sciencey” but they hadn’t had the science yet.  So, with those students, instead, they brainstormed around the word “energy” and then came back to the video.  On the other hand, in a calculus based physics course they used a lot of “sciencey words” but a lot of the ideas weren’t right.

Energy as a topic is so broad, it’s almost a “non-topic.”  This activity brings out a lot of the different ideas associated with such a broad topic.  Another activity they’ve used with teachers is to have them take a walk and come back and discuss something they noticed that had to do with energy.  It can be challenging, then, to focus the ideas down.

UPDATE:  Rhett over at Dot Physics couldn’t help his twitchy fingers and analyzed the motion of the elephant in the video.  Check it out for some interesting physics (as well as his emphatic argument that elephants can’t jump).

{ 1 comment… read it below or add one }

Frank Noschese August 7, 2009 at 3:33 pm

I agree, the movie (as presented) doesn’t quite work to achieve the learning goal.

Math teacher Dan Meyer does a much better job with this with his “What Can You Do With This?” series at his blog:


I also like the “Roadrunner Physics” collection from physics teacher Dan Burns:


Leave a Comment

Previous post:

Next post: