March 04, 2011

"Prop Lab"

Since I started teaching Physics I always wanted to have good labs. I tried the usual do this, then this, write down this bit of info... Every lab report turned out the same. The only real variety came from the very best and the very worst students. Not exactly best teaching practice.  Not to mention they were painful to grade. And what were my students learning? How to follow directions? Yeah, that's what science is, following a recipe.

When I started doing "Prop Labs" I was sold on the idea. I can't claim to be the brain behind the idea, I can only claim to be a groupie gulping the kool-aid. The idea is to give the students a "prop" and then let them have at it. The goal is to let them create the research question, let them create the procedure and let them figure out how to process the data and draw a conclusion. It's also most like real science! Don't get me wrong, I provided scaffolding in terms of general brainstorming and giving approval on questions so as not to "waste" several days. I also wrote a lab guide and modified old IB rubrics to help guide them through the details. The ideas kids come up with are often ideas I'd never think of. Now that's real science.

In the past I've given them props such as magnets, springs, rubber bands, balloons, clay, electric motors and vernier probes. If I can think of 7-8 solid ideas for a prop then its probably a good prop, if I can't come up with no more than 5 then its probably a no-go, however sometimes I'll give more than one prop which can make use of a just "okay" props. In the past student ideas for clay have included:
  • Drop height vs. dent diameter in a sphere of clay
  • Temperature vs. dent diameter in a sphere of clay
  • Coefficient of friction vs. temperature
  • Resistive force (to a string pulling through the clay) vs. temperature

The first time a class does a prop lab, they look at you like your crazy, like your asking them to do the impossible. By the second or third time around they're in the groove and chugging along. Pretty awesome, but you do have to be prepared for the push-back. 

The outcomes are not always stellar, but most of the class, at least 80%, come up with great ideas and are able to gather interesting data and draw a conclusion. Its amazing.