Have the Lab Practical Early

what to do about lab

2YC Editor's note: It is my pleasure to welcome Jerry Godbout as a Two Year College (2YC) Lead Contributor. After living in the cloudy shadows of the Great Lakes region for 21 years (but the sun is always shining, right? Yes, above the clouds), Jerry's nearly two decades of sun deficiency is rapidly being made up for in northern New Mexico where since 2017 he is a chemistry faculty at the University of New Mexico-Valencia. POGIL is his main pedagogical method. As he humbly says,"The less I talk, the better." Jerry's formal interest in all-things-chemistry was birthed from a fascination with pyrotechnics (and other incendiary devices). A report on fireworks early on while a high school student warranted a call home. And his chemistry background has made him an accomplished beer brewer (Jerry's July 2020 post, Chemistry of Brewing Part 1: The Malt). Jerry's undergraduate and graduate careers (culminating with a PhD from Michigan State University and a post-doc at the University of Rochester) focused on matrix isolation spectroscopy. He frequently taunted the synthetic organic chemists that bragged about dealing with molecules 'so' unstable/reactive that a glove box or a Schlenk line was needed. The stuff Jerry made and studied was so reactive that the only way they could be studied was to trap them in solid neon, which required pressures less than 10-5 Torr and T < 12K. Now, in sunny New Mexico he zaps pretty rocks with an XRF gun and is trying to figure out if automated farming systems are resource efficient. Welcome Jerry...   

Since early March 2020, nearly every U.S. college and university transitioned to remote instruction, many with a week's notice. In the 4+ months since, every discussion with natural science colleagues about the transition to remote instruction came down to one question. "What are you doing about labs?" We might chat a little about the pros and cons of Zoom breakout rooms and plot the downfall of Chegg, but it still always comes down to the labs. In the hurried conversion in March, many valiant efforts were made to do the best the scarce time and resources available to us. Two of the more common solutions were making a recording of the experiment being performed and distributing data to the students for analysis, or the use of virtual labs, such as Labsterä. I haven't come across anyone that thought these were equivalent to the actual lab experience. Better than nothing– sure. The same thing? Of course not.

So, what about the Fall 2020 semester? My institution (University of New Mexico– Valencia), as of 4:30 p.m. MDT 31 July 2020, like most, is encouraging us to limit in-person instruction as much as possible and having only remote instruction beyond late November. Only about 9% of the sections we are offering in Fall 2020 have an in-person component. The bulk of the these sections are courses where an in-person experience is critical: mainly science labs,  nursing, and allied health. The remainder have been converted to some remote modality whether it be a traditional asynchronous online offering or a synchronous remote offering. Like most, we are all also planning for the possibility of a rapid return to exclusively remote instruction should conditions warrant.While an acceptable substitute remains elusive, this time at least we have foresight.

If you only had 4 weeks of lab meetings, what would be the most efficient use of it? For laboratory courses where proficiency in certain techniques is expected, I've considered the idea of creating a unit focusing solely on the lab skills and techniques that are normally covered throughout the entire semester and teaching it at the beginning of the semester. This would culminate in a practical exam very early in the semester, instead of its usual place at the end.

I should note at this point that what I am suggesting is completely antithetical to my usual pedagogy. I never describe the purpose of a lab activity as the mastery of a particular skill, such as titration to visual endpoint. I always frame the activity as finding a solution to a question or problem, such as determining the level of free fatty acid in a waste vegetable oil (WVO) sample. Once the students understand conceptually how the technique will afford and answer, then I delve into the mechanics of the technique. As an example, in our 1st semester STEM majors lab, the "titration" experiment is the first part of the synthesis of biodiesel from WVO. In this experiment, a sample of WVO is titrated to determine the level of free fatty acid present. In the past, this experiment has generally been scheduled in the 6th week of the semester; and there is a good chance that in-person instruction may last that long.

In this proposed scheme, all of the lab techniques are covered in the first few meetings, albeit with minimal context. Continuing with the titration example, this particular experiment requires the following laboratory skills:

  1. reporting a measurement to the appropriate number of significant figures
  2. reading a buret volume
  3. delivering a specific volume from a pipet, and
  4. titrating to a phenolphthalein endpoint (and all of the mechanical skills that involves)

These are the things I think we all agree that are lost in videos and simulations. Proficiency in these, however, can be assessed without analyzing the oil. Continuing with the titration example, all of these could be taught by having the students titrate an assigned volume of an acid solution with a base solution to a phenolphthalein endpoint. Their competency in this technique could be quickly assessed by the students' initial and final titrant volumes, and the color of the endpoint. Students could even be asked to posit when this technique may be useful. The conceptual part of the experiment could then be covered later once the students are familiar with the stoichiometry and the acid-base chemistry, at which point this could be treated as a "dry" lab. This could be done in-person or remotely, as conditions allow.

While splitting the techniques and their applications is less than ideal pedagogically, it does increase the probability of covering all of the technique-based objectives in the case of an abbreviated in-person semester.