Wednesday, August 25, 2010

They Might Believe Me Now

School started. Kind of without me. I never did get my classroom put together how I wanted it and I am really frustrated with the condition in which the previous teacher left so many things.*

But the modeling part is awesome.

The chemistry curriculum starts out with a six part lab that measures the change in mass under several different conditions. One of the key ideas that kids need to buy into here is that their data actually mean something. For so long, they have hurried through and ended up with numbers that don't tell them anything. It didn't matter because they never needed to use those numbers in any meaningful way.** They were TOLD what they should have gotten and that was good enough.

Not any more. During my workshop, we were advised to do the first part of this lab and then bring the kids together to discuss the data. It's pretty simple lab where the kids find the mass of a piece of steel wool, change it's shape and mass it again. Of course, the mass shouldn't change, and, of course, most kids don't notice all the little pieces that fall to the floor as they scrunch it up. Each group did the lab once and we compiled all those trials. Our data gave us absolutely no indication as to whether or not the mass stayed the same. This leads us into a discussion of being careful in the lab and paying attention to what they are doing.

So back to the lab we went. I wish I had a picture of the pure disbelief on some of these kids faces.

Kid: "You mean we are going to do it again???"
Me: "Well, were you able to draw a reasonable conclusion based on our data?"
Kid: "No, but couldn't you just tell us?"
Me: Evil laugh

We repeated the lab and compiled results. Guess what? Still no trend in the data.

So back to the lab we went.

By now they are kind of figuring out they need to pay attention. Third times a charm and we were able to show that we really didn't lose any mass.

But then, we had the next five parts to do. It took a day. We compiled the results. They did pretty good until Part Four. Our data was scattered everywhere.

So back to the lab we went.

Better. Getting there. Then we looked at Part Five.

So back to the lab we went.

By this time, kids are really getting after their partners for spilling a drop of water, and kids are checking and double checking their measurements. Then we started to graph Part Six. I got two bars into the histogram when it became apparent that they were going to have to redo that one too.

So tomorrow, it's back to the lab we go.

I just keep thinking about how if I had done this lab last year, I wouldn't have even given a second thought to how poor the data really was. Oh, I knew they weren't being as careful as they should and I would have to tell them that their data "should look like this," but I never could justify the time it would take to redo the lab.

This is different. Their data is going to shape what they know instead of the other way around. We have spent four days on this lab and I feel like we are accomplishing something.

And I am loving it.


*Although maybe not as much as my student aide, bless her, who has been busy attempting to clean glassware and cabinets for me.

**Guilty.

3 comments:

The Younger Rachael said...

Wow, I love this! I'm going to find a good lab that we can do over and over again till they get it right (with guidance, yes). Why didn't I think of this?

Mrs. Tenkely said...

You are creating excellent scientists and data collectors! Great job, I am having a ball reading your posts about the learning you did this summer and now how it is all coming together with your students.

Bryna Goeckner said...

With our late start to school and some Jewish holidays having delayed my start to school, I am planning to do this lab next week. I'm so glad you posted the detailed description of what you did. It will certainly guide me as I help form my students into scientists. You are so right about the benfits of taking the time to collect the data right and let the data be used to form conclusions!

My Menu