Flipping NMR

[stephen_habay]

[originally posted spring 2015]

We introduce nuclear magnetic resonance topics in the second semester of organic chemistry lab. During the first two weeks of lab, we spend time lecturing on proton and carbon NMR theory and spectral interpretation with some built-in time for students to work on practice problems, learn NMR processing software (ACD/Labs NMR Processor), and become familiar with our NMR instrument. In the past, I lectured for a little over an hour using PowerPoint, then had students work on several problem sets. This approach was less than ideal. Students got very restless over the lecture portion of the lab period and would later tell me that it felt like too much information coming too fast. Further, because I spent so much time lecturing, students didn’t have enough time to work through the problems and ask questions during the lab period. I began to look for a way to make the lab less overwhelming to students, more interactive and engaging, and incorporate more time for problem solving. I have been producing video lectures and flipping some topics in lecture for over five years now, with some success. Flipping a laboratory topic such as NMR seemed more and more appealing, so I decided to try it out this year.

I recorded my usual PowerPoint presentation, but instead of one hour-long video for students to watch, I broke up the lecture into five shorter videos (approximately 10-12 minutes each) focusing on NMR theory, chemical shifts, electronic shielding, integration, and spin-spin splitting. Students were given a week before the lab period to watch the videos and be ready to work problems. They were able to print the PowerPoint slides and bring them to lab to refer to them while working on the assignments. Students, while working in small groups, were given a graded multiple choice assessment to complete by the end of the period. This assessment was used to test the basic knowledge covered in the videos. Students were also given take-home assignments of spectral interpretation problems to be turned in the following week. One major difference I noticed was that students needed much more time to complete the multiple choice assessment than in the past, when I conducted the lecture at the beginning of lab. This could be a consequence of students not watching the videos (though nearly all students claimed to have watched them) or not having the information “fresh” on their minds. So next semester I plan to use this multiple choice assessment as a pre-lab activity instead.

Overall, flipping NMR worked out well for me because of the extra time I was able to spend with each small group of students, answering questions and discussing common errors/pitfalls. It was particularly nice in lab where the total number of students is much smaller than in a lecture class. The added benefit to students was that they were able to start and progress further through the take-home assignments during lab than in the past. As a result, students scored higher on the take home assignments, presumably because they were able to ask more questions and get extra help from me and from each other. The flipped approach seems to have helped me achieve my goals of making NMR more engaging and approachable to students. It was also enormously more fun than the traditional “lecture – then problems” approach used in the past.

One additional consideration in favor of flipping NMR is that the recorded videos can be made available to any lab instructor for use in their lab sections. This can benefit those lab instructors who are comfortable guiding students through problem-solving activities, but who might not be as experienced or comfortable with lecturing on the material. Moreover, flipping NMR (or other laboratory topics for that matter) could be very useful for coordination of content across the multiple lab sections.