You know the drill. Read the lab handout for homework. Come into class and take a pre-lab quiz.
What am I assessing here? I’m figuring out if my students read ahead, whether they know what each piece of glassware and equipment looks like and what kind of reaction they’re about to perform. I’m figuring out if they know the specific safety concerns for this lab and what pitfalls to look out for so all their work doesn’t get messed up somehow.
All before they’ve ever set foot in the lab.
Okay, now the students go into the lab and follow the lab handout. Wait, which one is the Erlenmeyer flask? How big should it be? How much water was I supposed to add again? Where do I find the filter paper? What about the sodium iodide? Eager to get through the entire lab before the bell rings, the students ask for help hoping for a quick answer, and I spend half the class period directing them to the lab handout.
But is this what chemists do? Struggle through the procedure? Not really.* The answers to all of the above questions are default knowledge. The chemist already knows what the Erlenmeyer flask is and where the sodium iodide is stored. The difference between the chemist and the chemistry students is that the chemist record procedures and observations. She thinks about what she’s doing as she’s doing it and can troubleshoot readily because she knows what to expect. The chemistry students are following a recipe, except they don’t know what or where anything is, let alone how to use it, and oh, the bell is going to ring in fifteen minutes. The actual chemistry, the cool stuff, the interesting stuff, is left to be thought about the night before the lab write-up is due, often being missed entirely or misunderstood by many students.
Over the summer, I attended an AP Summer Institute for AP Physics 1. One of the biggest takeaways was how to conduct inquiry-based labs. Essentially, here’s the question, here’s the equipment, figure it out, you’ve got this. I loved it and decided to use it for my AP physics class. But could I apply the same idea to my chemistry class? I thought my sophomores would need a little more guidance, but I didn’t want them to just follow a recipe. My students show up to school all the time with cookies and brownies and cake to celebrate birthdays. They put together epic bake sales to raise money. I know they can follow a recipe. But do they know anything about how their raw ingredients turned into a delectable brownie? I doubt it. They are not master chemists… yet.
So, instead of using the traditional approach – one designed for more experienced chemists – and risking the students getting ‘lost in the struggle,’ I try to shift the focus to the science that’s taking place. As much as possible, I aim to make lab more about the chemistry and less about the struggle. That means no lab handouts.
My students walk into class, shake my hand, see that I’m wearing my safety glasses and immediately know it’s lab day. They find their safety goggles, pull out their lab notebooks, write the title of the lab on the next blank page and in their table of contents. When the bell rings, I assign lab groups semi-randomly so they have to learn to work with different people.
Once we’re ready to get started, they see me hold up the equipment and demonstrate the setup. We talk about the glassware and what it’s purpose is, so they figure out whether the beaker or the graduated cylinder is called for. They see the filtration setup and learn what each piece is for. They know exactly what to do and what it should look like. There’s also a hand-drawn diagram on the board with instructions.
But before I let them loose, I can ask them specific questions: How many significant figures should you record? What will happen when you put this compound in water? What kind of reaction will this be? Oftentimes, however, it’s infinitely more fun to let them be surprised, not knowing that hydrogen gas makes a popping sound when it burns or that the two aqueous solutions will form a bright yellow powder when mixed.
So what do I assess? Here are my goals for my students:
Write good laboratory procedures
Since there’s no lab handout to refer to, my students write out all of their procedures. One challenge is to differentiate between procedures that are relevant: “In a 100 mL beaker, dissolve 1.042 g of NaCl in about 25 mL of water” and procedures that are not: “Find a weigh boat. Put it on the scale.” Their procedures should be numbered and easily followed by their peers.
Draw clearly labeled diagrams of laboratory equipment
My students see the filtration setup in my demonstration, they set it up themselves, and then draw a labeled diagram. Drawing their own diagrams tells me more about what they understand than them looking at a computer-generated picture on the handout. Many students, especially the artistically-inclined, really get into their drawings, which they will remember better than the diagram they would have glanced at on the handout.
Record complete data and observations
One of the nice things about moving more or less together as a class is that there’s loads of time to discuss observations within a lab group and even to hear what other lab groups in the class have to say. We can all stop for a discussion immediately after the cool thing happens! They don’t have to wait until I hand their lab notebooks back to find out that they didn’t notice the change in color or the formation of bubbles. By then, the lab’s out of their minds anyways and my feedback wouldn’t be useful. The students also don’t go through their entire data analysis only to realize they didn’t record enough significant figures while they had the chance.
Be proud of your lab notebook!
As a result of all of this work, my students keep up their personal lab notebooks instead of stacks of lab handouts and worksheets with data tables. I enforce lab notebook rules: write the date, use headings, write legibly in pen, no scratchouts, no whiteout. That last one hurts many of my students, who strive for beautiful, clean, crisp writing. On the bright side, I don’t mind if they write in black, blue, pink, or purple ink. My hope is that they are proud of their lab notebook and really make it their own.
Does it work? Jury’s still out on that. I think so. I plan to write another blog post about what their lab notebooks actually look like and how I can improve how I communicate my expectations to my students. This is my first year teaching high school chemistry. It’s completely different from being a graduate teaching assistant in a college chemistry lab. What I do know is that when we’re in the lab, my students and I are having fun, we’re talking about chemistry, and we’re not stressing out about much. I call that a win.
Are you willing to go without lab handouts? Let me know in the comments!