Foundations: Labs...

We are into full swing now!  I have brand new physics kids who are getting used to all of the policies and norms of my classroom...whiteboarding practices, SBG (and all that brings), packets, and more frequent assessments.  With all of this introduction to new practices and procedures I've been honing for the past few years, I enjoy the opportunity to share WHY I do things the way I do, and I hope the kids see (or eventually see) that everything is crafted to support their developing skills!


One area I haven't devoted an entire blog post to is labs.  Lab investigations are a big part of physics as they give students a chance to SEE physics happen...whether they're validating what they've learned or making foundational connections.  I often do the latter by incorporating labs at the start of a unit to let the students get a feel for a concept before we dive right in.  I mentioned in my post over the summer that I'm shifting to more qualitative lab approaches (emphasizing pattern recognition and reflection) as I've noticed the quantitative elements (data generation and analysis) seemed to detract from their learning.  Check out that post for more of my rationale for favoring this qualitative work.

Once the lab experience is done, the big question has always been...what now?  "Lab report" is the typical response.  But why?  Are these kids in a regular-level physics course with unsteady math backgrounds and a growing but limited grasp on physics going to benefit from this process of slight analysis and a lot of documentation?  I think no.  I don't think lab reports help students process what happened in the lab.  I think they get so focused on writing what they think I WANT to read that they get little to no value out of the lab report experience.  If a lab investigation's primary objective is to help students see how the content they're studying relates to the world around them, then why not have them apply the lab learning to other scenarios instead of simply regurgitating what they've already done with a bit of analysis thrown in?  To that end, in lieu of a lab report, I give lab-based assessments in which the students apply the skills and learning from a lab to a slightly modified/advanced scenario.  The assessments are tied directly to our course skills, like any other SBG assessment, but through the lens of the lab.  In this way, I am emphasizing the learning alone.  Below is an example of a lab assessment question I've asked after a lab consisting of analyzing the position vs time graphs of two constant velocity cars.
Sample lab quiz question physics disanto
Since switching to the lab assessment strategy, I've seen students more readily apply the learning to related scenarios.

AP® Physics

The advanced course is rather different.  The expectation in this course is that lab reports happen.  This expectation comes from both the dictated course curriculum and my school.  So I definitely do them!  Do I fundamentally agree that lab reports are critical to my students' mastery of my course skills?  No.  I still believe that at this early stage of scientific learning my students are striving to write what they think I'm looking for.  However, I also believe that my students need to practice effective, analytical communication.  The labs we do at this level are conducive to a substantive report and are excellent opportunities for this practice.

I only have the students complete one formal lab (with a lab report) per unit of study.  If we do any other lab investigations (which we often do!), those are informal (no report).  The students absolutely love the informal labs...the fun of playing with toys without the pressure of documentation.  Who wouldn't love that!?

I have two lab skills incorporated into my SBG system, one assessing qualitative analysis and one assessing quantitative analysis.
lab course skills disanto SBG
I use the same 3, 4, 5, 6 scale as described in my SBG posts to assess these skills and I include them on the cover page of every lab template in which the students write their reports.  I also provide guidelines students can reference during their report-writing at home.  If you are interested in checking out the nitty-gritty details, I've made the file available here!

These are my thoughts on and approach to labs.  I'm confident I'll keep shifting my approach, but this is where I am now.  I'm excited to see how the qualitative labs go with my physics classes, and my AP® kids submit their first report next week!


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