Leading with the Lab: How to Use Inquiry in a Flipped Class
Chemistry Teacher, Middletown HS South
When I first started teaching 15 years ago, I ran my classroom the way my high school chemistry teacher ran hers. A typical unit would start with notes. We would cover basic definitions and vocabulary that would be used throughout the unit. We would then move on to example problems. Students completed questions from the review sheet in class so the teacher could see they knew how to solve a problem correctly.
Daily or weekly homework was assigned to reinforce what we were doing in class. Five-point pop quizzes were given every couple of days to check learning retention. Somewhere in the middle or latter half of the unit we would perform a lab to give context to what we had been learning. The unit would close with some sort of major assessment, such as a test.
Ask a question
In that kind of classroom, lab activities are used to illustrate a point. Or more commonly, to prove to students why they need to learn everything the teacher has been teaching in the unit. However, science is exploratory by nature. Look at the steps of the scientific method:
- Ask a question
- State a hypothesis
- Conduct an experiment
- Analyze the results
- Draw a conclusion
Nowhere in the scientific method does it say “The teacher will teach all of the necessary information, and I will then conduct a lab to prove I can apply that knowledge.” The first step of any experiment is to ask a question. The problem we are running into in schools is that students do not know what question to ask. If you have never taken chemistry before, where would you even start?
Lead with the lab
What I was finding in my classes was the best questions were coming from the students after they performed their experiments, but there was never time to go back and explore those questions. I realized the problem is not the material—the problem is where the lab occurs in the learning process. So to remedy the problem, I began to incorporate inquiry-based labs before offering direct instruction through video.
I now begin, as often as I can, with a lab activity. I want students to be in the dark at the beginning so that their attention while learning the material is focused on the why. Then, after they have the basic information to perform more complex tasks, students conduct another lab to apply what they have just learned. The following examples from my gas laws and molarity/molality units illustrate this approach.
We start the unit by giving each group a Vernier LabQuest™, gas pressure probe, and syringe. Students are asked to connect the equipment and then change the volume of the syringe, noting how the pressure changes. As a large group, we derive a simple formula for this relationship. Then students are asked to change the volume 5 more times, recording the volume and pressure readings in a spreadsheet, which they then graph. The questions that often come from the class are:
- What other ways can we change gases?
- Why can we see our breath in the winter, but not in the summer?
- Can we change the pressure of a gas without changing the volume?
- Why doesn’t a balloon ever shrink back to its original size?
For homework, students watch videos on the ideal gas law and the combined gas law. All conceptual content is taught through activities in class; both of these videos explain how to solve gas law problems mathematically. When students return to class, I perform a demonstration using a potato cannon. Students have to explain how the cannon works on a Google Form for a quiz grade. We then use a gas laws simulation on the PhET Web site to explore the other ways we change gases.
Using the Vernier equipment once more, we perform a pressure versus temperature experiment, tackling “Can we change the pressure of a gas without changing the volume?” and “Why doesn’t a balloon ever shrink back to its original size?” This is a traditional lab, and students must answer conclusion questions and show all calculations in the extension questions. Following classes involve a gas stoichiometry lab, a “working day” for students to complete homework in class, another demo turned into a quiz, and a Quest. All of this takes a total of 3 weeks or seven 80-minute blocks.
Students begin the unit by making fruit punch drinks. They can make the drinks to their taste. The stipulation is that they must measure the amount of drink mix in grams and the amount of water in milliliters while they are doing it. Then they make a second cup with an identical amount of mix, this time measuring the total volume of the drink at the end. The data analysis section walks them through the steps of calculating the molality of the 1st cup and molarity of the 2nd cup. So far, the words molarity and molality have not been used.
Next, students watch an instructional video (in class) about how to calculate molarity and molality, taking notes. They then use what they just learned to answer an extension question about calculating the molarity of a fruit punch solution made by following the directions on the package. In the next class, as a quiz of their understanding of concentration, they must prepare a solution of a particular concentration. They have to show all of their calculations and their solution is tested with a Vernier colorimeter to verify their results. Students work for the rest of the block on practice problems. Total time for the unit: two 80 minute blocks.
A nontraditional flip
These activities are not a “traditional” flip. Since the objective of the activities is to teach the material, instructional videos become the method for explaining material that is procedural, such as how to use the ideal gas law. The question that drives my lesson planning is:
What is the most effective use of my face-to-face time with my students?
I want my students engaged in problem solving when we are together so I can see how they think and how they can apply their knowledge. Could this be done without instructional videos? Probably, but the videos allow students to move at their own pace and receive support from me at the moments they need it.