Tuesday, December 11, 2012

Soil Permeability and Porosity Lab

Soil Permeability and Porosity lab: 3 student versions from STEMmom.org

While on my journey of learning what inquiry is NOT, I now realize that I might have had a smoother transition if I had seen some of the labs I was used to doing to compare to higher-level inquiry labs  that  have similar goals. So when I have time, I've been modifying the labs I post to include both a cookbook version along with an inquiry version.  At the end of this post I offer a free single download that includes three versions of the same lab, a coobook version, inquiry version, and science notebook inquiry version. 

Cookbook Version of the Soil Permeability and Porosity Lab 


The cookbook version of this soil lab provides a list of materials, a detailed procedure complete with directions on how data should be collected and recorded. The labs have pre and post lab questions that help students process what they learned from completing the lab experience. Although the term "cookbook lab" is usually said with distain, they have their purpose. My suggestion to you is to be sure you can tell the difference between cookbook labs and the varying levels of inquiry, and use them purposefully to help build students up the inquiry levels throughout the year. 

Student working on Soil Permeability and Porosity lab: from STEMmom.org

Materials needed for Permeability Lab
  • water
  • gravel, sand, and dirt (about 1 cup per group)
  • funnel
  • 3 coffee filters
  • ring stand (optional...we didn't have them)
  • stopwatch or watch with a second hand
Materials for Porosity Experiment
  • water
  • graduated cylinder (100 mL minimum)
  • 6 clear, plastic cups
  • permanent marker
  • metric ruler
  • large, medium, and small pebbles (about 1 cup per group)

Soil samples for a Soil Permeability and Porosity lab: from STEMmom.org

Inquiry Versions of the Soil Permeability and Porosity Lab 



I have two inquiry versions of this soil lab. Both versions have students gather and request the  materials they'll need to meet their challenge.

Inquiry challenge: "Develop a way to measure soil porosity and to develop a way to compare the permeability of different soils."          
The inquiry versions lead students through brainstorming, and then ask them to hypothesize which samples have the most permeability and porosity. Both Inquiry versions refer to "Play Time" which is where they are guided by questions and given time to play with their materials to test ideas they have before they write a procedure they will use as a compare their soil samples. Students doing an inquiry version of these soil labs come up with their own data tables in which to put their results. 

The difference between the two inquiry versions is that the first leads students a bit more than the third version, which I call the "Science Lab Notebook" version. In this third version I don't provide any post lab questions, instead, I gently guide students in how to write a lab write up using the following categories: Procedure, Data and Results, Analysis and Conclusions, Limitations, and Social Applications.       

Final results of Soil Permeability and Porosity lab: from STEMmom.org

I've been working with my students to increase the level at which they develop procedures themselves. Therefore, we did the first inquiry lab. I am concentrating on having them "play" and then develop their own procedures for labs we do. While I don't have them memorize the phases of the scientific method, I am introducing them to the lingo; contstants, control, manipulated (independent) variable, responding (dependent) variable, extraneous variables, control groups vs. experimental groups. You'll notice in the post lab questions, I'm getting students to think about these things. 


Challenges of Implementing Inquiry

I am finding that inquiry is easier for me to teach when I'm teaching a concept outside of my STEM passion area. For me, my passion is biology. I find I hold too closely to the procedures I used when learning a lab, and I have too narrow a view of what I think students should be learning. For this soil lab, teaching at an inquiry level was easier for me because I'm not as familiar with how scientists actually perform these measurements in their own research. My goal was not for them to figure out how scientists do it, but to find accurate, measurable ways to compare differences in soil. I'm more concerned about the scientific research thinking process, then the content-specific answers they come up with.  

In Inquiry Learning, Encourage Students to Admit Being Wrong


At this stage in their learning, students want to design an experiment, and then be able to say "it worked." However, because I let them design their procedures, there is a possibility that the method they chose didn't test what they thought it would. An important question to ask students, is "How confident are you that your results answer the question you set out to answer?" You'll need to ask this question in a variety of ways. Such as, "Is it possible that the method you designed, gave you misleading data? How could you improve your procedure to fix this?" In this particular lab, student should address how well their procedure measured permeability and porosity. We've got to stop students thinking they should "get the answer" the first time they try. STEM is about designing ways to find answers, and rarely can we do that the first time!     


Soil Permeability and Porosity lab: 3 student versions from STEMmom.org

All three of these labs are available for FREE at my Teachers Pay Teachers store. Please visit if you'd like to download a copy of these labs. I'd love to hear from you if you download this file! Leave me comments here, or at my TPT store!

If you like having options for labs, another lab you may want to check out is my Marshmallow Flight Lab where I provide both a cookbook version and an inquiry student version. 

2 comments:

  1. Great post! I get lots of homeschool moms telling me how frustrated they are when an experiment doesn't work the way the "cookbook" says it should. My thought is "Great! Figure out why. That is research and inquiry. That is science!" Science projects that allow students to design their own protocol and measurement strategies are great for allowing students to actually be the scientist!

    ReplyDelete
    Replies
    1. Marci, I know what you mean! We, as homeschooling parents, and as classroom teachers need to be ok with being uncomfortable! Things don't always "work" the way we think...but it should cause us to think! Did it not work because the data are telling us something significant? or because of something we did in our procedure? Like you said these are the golden opportunities we have to really think things through, and maybe design additional test to figure it out!

      Thanks so much for your comment!
      Darci

      Delete

I love comments! Would love to know you were here! :)

Related Posts Plugin for WordPress, Blogger...