Results of Four Years of Teaching the Mechanism

I adopted the Karty textbook four years ago.  I had been using a book organized by functional group but focused on the subject from a mechanistic approach. When it came to choosing a new textbook, I reviewed most of the textbooks on the market and asked my current and previous students their opinions of each one.  Many of my previous students had suggested over the years that they wanted a book that was easier to read, and that provided explanations that were detailed and specific enough to help them understand the material in a broader sense.  Overwhelmingly, the Karty textbook was the top pick, with many students remarking “why aren’t we using this book now?”

Since my own preferences and my students’ inclinations were aligned, I adopted the Karty textbook.  This spring, I found myself looking back on the previous four years and reflecting on what differences I have seen in student learning outcomes after making this change.

I have noticed two trends: the overall class average on the ACS two-term exam has gone up consistently, and overall student understanding of the material has also increased.

The first trend is easy to quantify just by looking at the scores: students are getting higher scores on average.  Before I started using the Karty text, around 20% of students were scoring above the 50^th percentile on the ACS exams.  After switching, I saw this number increase steadily over the past four years up to this last spring when 70% of students were scoring above the 50^th percentile.

The second trend is a little harder to quantify.  I say that overall understanding of the material has increased, not just due to the scores students have earned on exams, but instead this impression is based on the number of more detailed and specific conversations I have had with my students that reflect a better understanding of the concepts.  When I was using a textbook organized by functional group students who struggled to learn organic chemistry would tend to give up about halfway through the spring semester due to the overwhelming number of reactions that they needed to learn and were responsible for.  Now, a larger number of my students, including the ones who struggle to learn the material, are staying engaged with the course throughout the entire year.

I am also seeing a larger number of students who consistently improved their exam grades as the course went on.  Additionally, their writing has also improved with better written lab reports than I have been used to in the past.  I require two full length major lab reports each semester that are modeled after the general way a publication is put together in a journal article.  The introduction and discussion sections of these lab reports require students to explain their understanding of a reaction from their lab, explain the mechanism, and how the reaction fits overall within organic chemistry as a whole.  I have seen an increasing trend within my students where by the end of the second semester, they are able to explain the mechanisms and apply them to reactions that aren’t found in the textbook. Their writing reflects a much better understanding of the material than I had observed prior to switching textbooks.

Probably the best example reflecting better understanding is this past semester: I had a literature assignment where students were required to pick a communication article from the primary literature, in this case either from Organic Letters or Tetrahedron Letters, which had a new reaction in it and explain, as well as they could, the mechanism of this reaction.  It was great to see students look at a reaction they had never seen before and try to explain it using the elementary steps they had learned in Chapter 7.  The vast majority of students did a great job showing how they could apply the elementary steps to a piece of current research.

Overall, the decision to switch to Karty’s textbook was a positive one for me and my students.  By the second year my approach to teaching changed and I noticed how using a functional group organization had boxed in my personal teaching style to only thinking along traditional lines.  I was less concerned with getting to reactions as quickly as possible and really spent a lot more time focusing on the basics (like thoroughly covering trends in anion stability) and that has really made a huge difference in student understanding of material for the remainder of the course.

-Nathan Duncan, Maryville College