Kevin Davies

Making Lab Technique Videos

Blog Post created by Kevin Davies on Nov 16, 2016

In lab, I’ve constantly found myself trying to come up with a good way to explain how students should do a measurement and take a reading.  This is a challenge both in my General Chemistry I labs and in my Analytical Chemistry course. 

 

Our goal is to teach the students how to (literally) look at the experiment the same way as an expert would, and I have been convinced for some time that technique videos are a great fit for flipped chemistry approaches:  By moving the lecture out of the lab, we leave more lab time to actually do the experiment in-class, focusing more time for feedback on the nuance of their technique.  Further, with technique videos, students can revisit the techniques (finesse included) as they think through their post-lab assignments.

 

I have tried to make technique videos in past semesters, but these have had a number of shortcomings that undercut my goals.  Few humans I’ve met have more than 2 hands, myself included.  Using one to hold a camera left me with a clumsy and artificial technique, which is a tremendous challenge in demonstrating analytical-quality lab technique.  The focal point of my camera slid in and out of focus, making it hard to see a meniscus or glassware markings.  The shifting field of view made it challenging to tell what I’m actually looking at.  And, worse still, the viewer could only see where my eyes OR my hands were working, but not both simultaneously.  A tripod-mounted camera addressed some of these issues and allowed the viewer to see more of the gross movements of a technique, but cost us all the close-up details that are so critical.

 

Recently, I decided to blend these two approaches in conjunction with David Jaeger, the Director of Web, E-Learning, and Publication Services here at Florida Gulf Coast University.  Dave had approached me about comparing the efficacy of learning from first person vs. third person views of laboratory techniques.  In order to make Dave’s videos, we worked together to list each discrete action or reading that I took when making a laboratory measurement.  We planned to make videos for the use of an analytical balance, a volumetric pipette, and a buret; I use our list of ‘actions’ to guide me, and Dave monitored what else he observed me doing.  This dual approach captured the complete sequence of events that took place while doing a measurement, and ensured that my own experienced technique did not create ‘blind-spots’ where I forgot that a student was missing a skill or instinct.  Dave plans to run experiments with student subjects to determine when the first- vs. third-person view is more useful.

 

My focus was different, but collinear with his goals: I wanted to develop videos that would teach the students how to best use the glassware with analytical-quality lab technique.  My thinking was that since the first- and third-person views have complementary strengths and weaknesses, I might be able to address the weaknesses of each by combining them.  I decided that I wanted to develop a split-screen video.  One portion of the screen would be my direct point-of-view recording (1st person, which I dubbed the ‘expert eye’ view) while the other was a tripod-mounted over-the-shoulder recording (the ‘wide view’, aka 3rd person over-the-shoulder).  In practice, we had two wide-view cameras, and I retained them both in the final test video.

 

I will be trying this approach in Spring 2015 with my Analytical Chemistry students, and will be making these videos available to this semester’s General Chemistry I teaching team.  An example video can be found at the link below, and I welcome feedback!

 

 

Helpful advice in making similar videos:

 

  • For the first-person view, we used a pair of video-recording sunglasses with clear lenses swapped in to make them look more like safety glasses in the video. (These glasses are often worn by action/adventure sports participants to record videos.)  The camera is in the nosepiece. 
  • It was challenging to keep the hardware in-frame, since the camera and your eyes may not be pointed quite the same. After some trial and error, we found that it was best to calibrate the glasses before recording.  We accomplished this by making a crosshair on one lens with dry-erase marker, then recording for a few seconds to see it the videos was correctly centered, then moving the crosshairs and repeating the process until the video was satisfactorily centered.  Particularly if this crosshair is on the eye away from the camera, this is invisible in the final video – and is hard to notice even when the other camera can see the eyewear.
  • A backdrop is advisable, since the cameras will be recording at different angles and unrelated and distracting background material can easily enter the frame. Even with a heavy cloth backdrop (borrowed from the Campus-related PBS TV station) and the blinds drawn, you can still see light seeping through the backdrop.  We set the curtain up in a u-shape around the bench to best mask the surroundings.
  • In order to sync the two camera recordings later, I clapped my hands a single time – this provided a sound cue that we could easily spot in Camtasia in the audio track, and provided a time=0 point.
  • I did my best to not talk during recording, unless I did so while keeping my mouth as still as possible (ventriloquist style). In test runs, we both found it deeply distracting to see me in the video talking out-of-sync with the new narration, and found that the original soundtrack recording was usually too noisy to understand due to hoods in the background and such.

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