Friday, March 9, 2007

Chemistry Labs and Teaching

It is a truth accepted by everyone that especially in Science principles and concepts taught in lectures are best understood by the student when coupled to a laboratory experience where the student not only has a "hands-on" experience with the experiment but also must grapple with recording and analysing the lab in the context of what was taught in the course. So we believe.

The horrible truth is that for the most part the link between lecture and lab is tenuous at best. In many places the labs are so de-linked from the lectures that the lab are offered as a separate course (although perversely in such institutions the number of credit hours required to graduate is increased for science students to the amount of lab courses). It takes a student with a vast memory and a strong desire to make the link to actually benefit from the lab in the manner which was intended.

And then there are the microlab enthusiasts.

Some time in the 1990's micro scale lab procedures swept the discipline. It was everywhere and the rationales were many. Smaller amounts of reagents meant less risk and the same pedagogical goals were attained. In my opinion the same goals were attained because the intent of the lab experience was lost prior to the change to microscale and its popularity was simply the result of pragmatic lab management and prescient students falling somewhere between mind reading and "Clever Hans". We who love chemistry all remember the astonishment and glee that we knew in our synthetic labs when the procedures "worked" and gave us handfulls of product with crystals that you could kill aliens with. Conversely we also knew the hot acrid taste of crystal envy or the shame of prep-TLC inadequacy. Not possible when you have a mini centrifuge tube and the positive sign of reaction is a decrease in transparency. No, it requires bulk, it requires amounts where static cling from the vessel does not retain more of the product that you can recover.

But, it is almost over and it will be soon. We could see it coming and those of us of a certain age will remember our chemical youth with nostalgia. This story has been making the rounds (first to my eyes by a citation from Derek Lowe of "In the Pipeline" commenting on this link).

In my opinion the liabilities, poor link with pedagogical goals and cost (of teaching, maintaining and disposing) of chemistry labs will bring their demise. There will be a transition period where we will rejig our labs to run on nothing but consumer chemicals and ethanol but that as well will pass because the waste will just cost too much to deal with (because the safety officer will not see how bleach in the lab could be handled like bleach at home). The bell will also begin to toll for university research chemistry labs as well. It may take longer but it will have to happen as environmental concerns and the power of safety officers approaches an absolute level. At least some of us were around for the golden age of teaching chemistry both in learning and teaching.

"Pull out the projector Tommy we are going to watch a video of a chemistry laboratory."


Chemgeek said...

Just found your blog. It's right up my alley.

I teach at a small, liberal arts college. I have the pleasure of teaching lecture and labs for the same course. It is a lot of work, but I am able to correlate what the students do in lab with what we discuss in lecture.

We do titrations in lab right after talking about titrations in lecture, for example. I've seen too many programs where the lecture and lab are completely disjointed. Then the lab is just a training in technique rather than also a reinforcement of concepts.

Liberal Arts Chemist said...

Thanks for your comment.

Yeah, my university is too small for there to be much of an instructional level for staff so I end up creating the lab manual, setting up the labs, teaching the labs and cleaning up afterwards. The real problem is the fundamental ignorance of administration of just how much faculty time is involved in teaching labs.

On the other hand I must agree with you that the complete control of pace and content is brilliant and I do not see how the super sized universities can pedagogically justify the de-linking of labs and lectures. One large university near here decided that they would teach the labs as separate courses. It was a disaster on two counts. Students were taking the labs in different semesters than the lectures and they discovered that in chemistry the real money maker was the first year general chemistry course and the only reason a lot of students were passing the course was that they were getting high lab marks in combination with near fail lecture marks but the combination was a pass in the course. Their failure rate when they separated the lab from the lecture went through the roof.

Their solution was the dumb down the lecture.

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For a while it was all about research and then it was all about teaching and now it's all about trying to find a balance while teaching at a small liberal arts and science university.