Many teachers struggle with successfully scaffolding the experimental design process. It took me a long time to give up control and correctly set the scene for students to be successful when designing experiments.
Here are a few tips to help make sure that your inquiry activities are successful.
1. Make sure your inquiry activity should really be an experiment.
This may seem obvious but I think some teachers believe that everything should be inquiry based. I don’t necessarily believe that is the case.
Not all laboratory activities are experiments. Many things that we do in the lab with students would be better categorized as observation activities. During an observation you will likely provide students with a set procedure for them to follow. It may be essential for them to follow a specific list of instructions in order to get the proper result.
For example, there is an activity I love to do in my classroom where students extract DNA from a strawberry. This allows them to see DNA and make observations, but they aren’t going to do anything with the DNA beyond that point. There is no experiment to design. In the era of NGSS, I still believe this is a valuable activity, but it isn’t an experiment.
2. Start with a question.
Give them a question that will get them thinking. The question should be something that is relatively easy to test, but it also should be a bit open ended so that there is potential for students to attempt to answer the question in different ways. For example:
- Do objects with different mass fall at the same rate?
- What factors affect plant growth?
If you are concerned that your question is a little too open ended or vague, you can provide them with a list of acceptable materials to keep them focused.
3. Make sure your students understand variables.
I don’t necessarily teach the “scientific method” in my classroom. My fear is that students believe that this is a list of steps that should be covered in a certain order. Adhering to this strict method won’t necessarily help them to answer their question.
Instead, I spend about a week talking about variables. In middle school, I talk about independent, dependent and constant variables. I also use this time to teach students about tables and graphs. Here are a few resources that I use in my classroom:
- NGSS Experimental Design: Independent, Dependent and Constant Variables
- Experimental Design: Graphing Variables
4. Keep it simple (at least in the beginning).
The first experimental design activity that I did this year was answering one of the questions above. Students were asked to design an experiment to determine if objects with different mass fall at the same rate. I provided them with a materials list (3 types of balls and permission to use their cell phone) and an outline and let them go.
It went very well. In fact, it just so happened that my principal did a surprise observation that day (with a district level administrator… eek!). I was worried that they would be alarmed by the relative chaos in my classroom, but they both loved the set up.
If you aren’t quite ready to have students design the entires experiment themselves, consider using one of your old pre-NGSS labs. Have them do the lab the same way that they normally would. Then, have them change one variable.
For example, the floating leaf disk lab is one of my favorite activities for measuring the rate of photosynthesis. (I don’t have one that I can share, but it’s on my list. For now, you can google it.)
The procedure is quite complicated so it wouldn’t make sense for students to design the experiment from scratch. Instead, I have students complete the pre-designed experiment. Then they read about factors that affect the rate of photosynthesis. They use that information to change one variable in their experiment and run the experiment again. This allows them to manipulate variables and compare their new results to their old results.
5. Require that they check in.
I have students check in after they have identified the variables in their experiment. I initial their document and ask that they check in again after they have written a procedures and created an outline for their data table (when appropriate). This helps me identify struggling students before they have gone too far in the wrong direction.
When they are off track I ask leading questions and refer them back to their interactive notebook.
6. Save time for revision.
This process takes a bit longer than running your pre-NGSS prepared activities, especially the first few times you try. Plan for them to take longer and don’t stress about your timeline. In my experience, students understand the results of their experiment so much better that it is well worth the additional time.
How do you successfully scaffold the experimental design process?
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