I have a photo of me and my oldest son taped to a shelf in my office. In the picture, I’m holding him up and we’re wearing matching red bandanas. He was about 3-years-old at the time (he’s 13 now), and I had a full head of bright red hair. But today, it’s almost all gray. Where did the time go?

In preparation of writing this retrospective post, I took a look back at my collection of organic chemistry syllabi and found that I had switched organic chemistry textbooks for the fall of 2014 when I first started using Joel Karty’s Organic Chemistry: Principles and Mechanisms. That puts me at almost 6 years of use, a perfect time to do some assessment. So now, as I’m looking backwards in time, I do miss having melanin in my hair, but I don’t miss my old organic chemistry textbook.

My Students’ Grades Have Gone Up

I have previously written about the struggle to encourage chemistry students to use the textbook more, which is a struggle that continues to this day. So honestly, I was a bit skeptical about the idea that switching textbooks might improve my students’ overall performance…but it seems that it really has, and I think I know why.

I took a look back at my gradebooks for the spring semesters from 2007 to 2019, and it is quite clear that right around 2015, after I changed textbooks, the overall student averages have gone up about 8% (to an average student final grade of 80%). Digging a little bit deeper, the quizzes that focus on mechanisms are notably higher on average. The strongest examples are the three quizzes I give on the alkene mechanisms in Chapter 11 and 12. Putting all of the data together, the class average was 7.25/10 before Karty and 8.5/10 after Karty. My class this semester averaged 8.9/10 on those three quizzes!

For this analysis, I chose to look at organic II because that is the semester where I focus most of the class time on reaction mechanisms, so I thought the results would be more consistent. The students who take and finish organic II are generally the ones who go on to complete their science degrees.

I believe the consistent approach I use with Karty’s organic chemistry textbook has led to students’ being better at reaction mechanisms and ending up with higher grades overall. First, here’s some context. For the majority of the first semester, I work on teaching students the fundamentals of organic chemistry. The first five chapters cover bonding, geometry, stereochemistry, naming, and structure drawing, among everything else. We spend the second half of the fall semester covering reaction mechanisms and the underlying explanations that drive the rest of the textbook. Overall, I spend a lot of extra time on the fundamentals, especially on Chapter 6, where the explanations for acid and base strength are covered along with the proton transfer mechanism. This chapter, in my opinion, is the most important chapter in the book (a topic for another time, perhaps).

The textbook’s organization by mechanism instead of functional group, which places the naming sections in separate parts, breaks them apart in a way that allows me to structure my week similarly for each chapter covering a new mechanism. Each week, students are expected to know a certain number of reactions from start to finish (just draw the products), as well as some of the full mechanisms, and they also need to be able to explain the reactions. For example: Why does the bromine add to the more substituted carbon in HBr addition to alkenes?

To keep the students on schedule with learning mechanisms, I give weekly homework (due every Friday) and a weekly quiz (also every Friday). Having the chapters organized around mechanism patterns allows me to make a much more consistent experience for my students. In the electrophilic addition to nonpolar pi bonds chapters, the reaction mechanisms of HBr and Br2 additions are different enough that they are separated into different chapters. This allows students to focus on learning patterns instead of memorizing them.

When organic chemistry students know exactly what is expected of them, and how much time they have before they will be tested on the material, they can figure out how to study the most efficiently. This isn’t a perfect system, and there are a lot more concepts for them to learn besides reaction mechanisms, but the addition of Karty’s book to my course almost 6 years ago has really helped make a big difference for me and my students.

-Andrew Robak, Keuka College

Feel free to share your thoughts in the “Comments” section below, and stay tuned for Part II of this post next week!

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