09 March 2012

Flipping over assessment

Not to give away part of my presentation for the Flipped Class Conference in June, by I have to talk for a minute about how assessment has changed in my class.  While there are still the typical assignments (HW, quizzes, tests, labs) I have tried to not only make everything objective-based, but also put some sort of inquiry into as many as possible.  This has been the most fun in my recent 5pt quizzes.

I have always used my quizzes as a way to do a quick check for understanding and to keep the students studying the material throughout the unit instead of the night before the test.  When I started the last unit I was looking at the typical problems I put on the quiz and decided that it bored me to even type them up in the first place.  The problem was a Boyle's Law problem (Pressure and Volume are inversely proportional) and I remembered I had this great demo involving shooting a slug of potato across the room.  So, I told the students to take out a half sheet of paper, did the demo (spraying potato everywhere) and told them to explain the demo using what they knew about gas laws.  The entire class got a perfect score.  But the best part was they had fun for that quiz.

So we are now in the Solutions unit and I needed to come up with a good quiz question.  I focus heavily on making solutions and what better way to demonstrate that you can make a solution than by making pink lemonade.  I told my students they were to calculate and write out the procedure for making a solution that was no less than 1.0 in concentration (Molarity or molality was up to them) and then make the solution.  They jumped right into it and immediately did it wrong.  They didn't know they were wrong when they did the calculations because everything looked perfect.  It was when they went to make the solution and overflowed the cup that everything became clear.  What students typically forget is that when you add solute to solvent the volume increases.  Easy to say, but better to experience.

One of my best students gets a 4/5 because of this and begins to negotiate with me on how he can earn back the lost point.  So I looked at him and said that if he can figure out the concentration of a solution made from directions on the back of the container, he could have his point back.  And off he went.  15 minutes later he is back with all of his calculations.  The reason this was challenging is the measurements are in fluid ounces for the total volume and tablespoons for the powder (which we assume is just sucrose), neither of which are units of measurement we use.  I look at his calculations and notice that he had converted everything to grams and milliliters.  As soon as I open my mouth, he interrupts with "I Google'd the measurement conversions that I didn't know."  Well, it turns out that pink lemonade has a concentration of about 0.237M.

The key to this story is that when you move to the Flipped Classroom everything is about the conversations. There is no question that this student understands the material.  Sure I could have given him a traditional written quiz and he probably would have earned the same grade.  But he was far more engaged and will probably remember what he learned from this experience far longer than doing some problem from a textbook.