In my previous blog about how I help students in the lab, I explained that I have been keeping a record of the questions that students have been asking me over the last academic year during laboratory practical classes.
The most interesting type of questions were those that I categorised as helping students make decisions, and I listed all the questions I have been asked under this category.
In this blog I’m going see if I can dig any deeper into understanding what the source of these problems are and therefore, what implications this could have for laboratory teaching.
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Coding questions by problem type
I wanted to uncover the gaps in the students’ ability to solve these problems, so I investigated if coding these questions by problem type would highlight the types of problems that students find difficult. To determine what how each category of problem should defined, I considered the background knowledge required for each solution.
The code Theory: techniques was assigned for questions such as ”*shows TLC plate* Is my reaction complete?” and ”Do I add the aqueous layer to the organic layer or the organic layer to aqueous layer?” as the solutions to these problems can be solved by understanding how practical techniques works.
For questions such as ”Should I perform a column or a recrystallisation?” the code was Experimental Design: purification. I saw this as being distinctly different to questions relating to the theory of techniques. Here the students are trying to decide when use a technique. This is itself is a different to simply different to understanding how the technique works.
For questions such as ”I used wet methanol instead of dry methanol. Does it matter?”, I assigned the code Theory: how the reaction works because, as it answered by with an understanding the theory of the reaction being performed, such as in this case, if the reaction is air sensitive.
Hopefully, the other codes are pretty self explanatory. Here’s the list in full after reordering the questions by solution.
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Analysis and implications for improving lab teaching
From this coding we can see that a large a proportion of the problems are linked to students’ lacking an understanding of the experimental techniques and the reactions they are performing. Quite often, the understanding of a reaction is learnt after experiment has been performed during when lab report is written. If more time was spent at the beginning of the reaction discussing the theory of the reaction and how it related to the procedure then perhaps students could solve these types of problems.
Similarly if students had a better understanding of the techniques they are performing then we could expect improvements in problem-solving in this areas. Interestingly, the number of questions relating to experimental design shows we should also teach students to plan and design experiments as well.
From an ad-hoc exercise has for me (unexpectedly) generated some interesting results. There are of course some limitations to what I have done, the most glaring of which is the fact it was only based on questions asked of me and I didn’t record the number of times I was asked the same the question. This is something I will look into further over the next year by gathering more data, and involving more demonstrators to record their help to students. Watch this space.
Mistry Research Group 