AP Biology: Opening Day -- The Great Toll House Cookie Challenge

I decided on a new opening activity this year. I got the idea from a share session with other teachers at a Cornell (CIBT) workshop I attended this summer. I think it specifically came from Christine Courtsunis.

THE GREAT TOLL HOUSE COOKIE CHALLENGE!
Lab work & experimental design is much like cooking and following a recipe, so I decided we should bake cookies on the first day... but only as an analogy to experimental design. I baked a batch at home using the Toll House Cookie recipe from the Nestle's semi-sweet chocolate chip package. I followed the recipe to the letter -- which for me is REALLY difficult, since I am one of those cooks who modifies as she goes! Now my batch served as the original "experimental result" and the recipe was the experimental design. Now it was the students turn. I threw down the gauntlet -- can you bake cookies just like mine by following the recipe as well. I brought in a wide range of supplies:

• different flours (but all were called "All Purpose" like the recipe called for
• 2 different brown sugars (light & dark)
• 2 different kinds of nuts (pecans & walnuts)
• 2 different salts (Kosher/non-iodized & iodized)
• 2 different butters (salted & unsalted)
• 2 different sizes of eggs (medium & X-large)
  

Then the students were put to the task of making their cookies.
I had made prior arrangement with the Home Ec. department to be able to bake the cookies in their ovens once we were done mixing in our room.

Well, I am not sure what the students learned (yet), but I certainly got an interesting education in the end! Well, I envisioned students pondering whether to use light or dark brown sugar or salted vs. sweet butter and then asking me which one and I had my answer ready "What does the recipe say?" Because, in fact, the recipe doesn't specify... it only says butter. So this would blossom into a lesson of specificity of experimental design descriptions and the unexpected effect of unintended confounding variables.

Aaaah.... all the best laid plans of science teachers gone aft agley...

I quickly learned that students had little experience following recipes and had no clue how to proceed correctly. Yes, they dove right in, but I had groups just adding ingredients to each other as they were listed in the ingredient list or in random order -- not based on the instructions. So I saw butter and flour mixed together first... or butter and egg mixed together first... or all ingredients poured into one bowl and then finally mixed! Yeeesh!

So we now have to move this into a discussion of how to actually FOLLOW DIRECTIONS if you want to be successful in AP Biology.

Now, in all fairness, I think I created some of this situation by talking too long in the first period and rushing them into starting this. An approach that I will correct for next year. But I still had one group of young women who followed the recipe to the letter and even finished before everyone else.

I do have to remember to STOP adding the rush factor with any of my activities!

So tomorrow I am going to try to resurrect this lesson from the cookie crumbs and see if we can talk about variables. Then onto real hypothesis development.

FOLLOW UP
Next day -- lesson resurrection day...
I started off by explaining what my goal had been for the lesson of the previous day and then quickly segued into what I learned. I elicited from students descriptions of how they had not followed directions (procedures) and how they could have improved. It actually was a great discussion -- they can be prompted to get it!

We baked our cookies (we had to refrigerate them overnight because of lack of time) and then sampled across groups. It was amazing the variation in results we found from crispy flat cookies to cake-like puffed up cookies. This gave me the opportunity to compare to unwanted variations in experiments and then introduce the concept of confounding variables. I think we will be able to build on this foundation throughout the year!

And we gotto eat chocolate chip cookies, ta'boot!
And while munching we started to learn about the nature of science and generating hypotheses... more on that later.

I will definitely use again!