The Mistake Game, v1.0

Today the physics classes played the mistake game for the first time.  We've been talking about making predictive models, and they've read (refreshed, hopefully) about several different algebraic models that will come up frequently: proportional, linear, quadratic, power (>1), power (<1), log, exponential growth, and exponential decay.

This morning, I prepared each group's whiteboard with 6 graphs, and gave them the task of identifying the algebraic model or models that would correspond with the graphical models given.  They also had the task of making a (hopefully, just the one!) mistake, and of justifying that mistake in the same way that they justify the others to the class.  Per Kelly O'Shea's awesome suggestion, I framed the discussion by having them ask questions of each other, rather than "hey, that one's wrong!"  They got in the hang of that pretty well, and I tried to get in the hang of adding not much to the discussion. 

It's easy to let presentations be valuable only for the presenters, because we tend to let the kids off of the hook as far as the burden of real probing questions goes.  This did a great job of keeping everyone on their toes, and will hopefully set the tone for the oh so many productive whiteboard discussions that we'll have this year!

Here's a good representative.  Can you find the mistake?