Letters to the editor

Re: ‘Flipping the chemistry classroom’ series

The series ‘Flipping the chemistry classroom’ by Nicholas Key was excellent. Nicholas and his colleague David Greisman deserve kudos for sharing their experiences; their results are impressive. I base my opinion on experience. My serendipitous conversion to a form of flipped learning took place in 1974-75 when I was a faculty member at Dawson College (CÉGEP)1 in Montreal. A colleague (the late Peter Berlow) introduced the Keller Plan2, also known as PSI (Personalized System of Instruction) to teach general chemistry; I was sure it would be a fiasco, but he was successful and I was hooked.

PSI Learning

  • No lectures
  • Printed materials
  • Study guide
  • Objectives
  • Self-paced
  • Mastery (80%)
  • Student proctors

The success of the PSI method totally changed my mindset about teaching and learning. From 1975 to 1980, I was one of a small group of chemistry and biology teachers at Dawson College teaching mainly by this non-lecture methodology. Students not only learned chemistry well by this methodology, they also became more independent and responsible learners.

I encourage teachers to try flipping, at least in a small way, where circumstances permit.

It will take time and effort to create the extra materials needed for a flipped course but the payback time is fairly short and worthwhile as long as you can be sure the course will not change over a reasonable timescale. The effort will be reduced if you can find kindred spirits with whom to share the work of creating the materials. This work, and the preparation for laboratory work could all be done before teaching begins.

Flipping will not be paradise for the teacher. There are no lectures, but be prepared for the time Nicholas Key and David Greisman spend on checklists and checkpoints. This is probably not work you can share with anyone else. At Dawson College we had student proctors, enrolled in a humanities option course, to help tutor and grade quizzes. They were students doing well in the course, or students who had previously completed the course with good grades.

It is now 35 years since I left Montreal, but as I recall, we had a dedicated classroom for our courses. Attendance was not compulsory, but even so, with tutoring and real-time grading of unit quizzes, it was often quite busy and the noise and activity was disturbing to students writing quizzes. Privacy was also an issue when giving feedback to students. I wonder how Nicholas and David deal with these issues?

[Nicholas’ response: When I was approached to write this series of articles, I was told that the purpose was to begin a discussion on different methods that are being used to teach chemistry (flipped learning included, of course.) It appears as if the discussion has begun! With respect to the questions presented by David Cash, I will try to answer each in turn as best I can.

In terms of how we approach feedback to students, privacy is always a concern. When these checkpoints are completed, the students approach us, and we work through answers together, one on one. The feedback is formative, and meant to be supportive and constructive. Since it does not form any part of a summative grade directly, we have yet to have an issue with privacy — though it is certainly worth consideration when any form of feedback is given.]

Mastery2 is another issue. At Dawson we used a model of 80% mastery on unit quizzes that were essentially identical to the practice quizzes in the study guide. The student could not proceed unless this mark was obtained, so we had multiple versions (four) of each quiz. Even so, weaker students found this to be a formidable barrier. I wonder what exactly do Nicholas and David mean by their use of the term “mastery”?

[Much like our articles, I notice that David Cash has included quotation marks around "mastery". Our idea is that students complete these checkpoints to our satisfaction and answer any of our additional probing questions before being permitted to move onto the next section of the checklist and corresponding checkpoint. The questions are similar to those that they might see on a quiz, test or final exam. Some are conceptual questions that evaluate their understanding rather than just cursory knowledge. There is no mark assigned to these checkpoints. The term "mastery" is not our own, nor is the concept new (I recall studying it in teacher's college) and I would challenge the idea that the students have "mastered" the concepts, but at the very least we know that they have done the appropriate work and can communicate their understanding to our satisfaction. That is our idea of "mastery" — a demonstration to us that they can solve appropriate problems in the current area of the course before moving on.]

Looking at their Table 2 in Part 5 (April 2015 issue) it seems that completion of the checklists and checkpoints is not compulsory. I wonder if this is by choice, or because making it compulsory is not allowed in the school system? I wonder why so many students do not follow the checklist-checkpoint system, and what can be done to encourage the non-participants to get with the program?

In regards to compulsory completion of checkpoints, this has been a point of some debate. To be quite honest, this is an area that we are still working on. Currently, David Greisman and I are using different approaches. David has all his students write the checkpoints on the same day — providing a deadline. He has a discussion with those who do not meet his standards.

I have each student who has completed the work and checkpoint show me — if they want. I then discuss each checkpoint individually. At the beginning of each semester I show students my checkpoint stats. It is up to them ultimately whether they choose to use the checkpoint method or not. I struggle with those who choose not to, but even while using videos for content presentation, reaching 30 students in each class on a regular basis and providing the appropriate amount of time to each is extremely difficult. The challenge is to find the time to help those who need the most help. To those that don't "get with the program" — the sad reality is some students will resist tooth and nail — they may not receive the full amount of my time and motivation necessary for them to be successful. And as in all courses, there are some students who are misplaced, and some who just do not buy in — for whatever reason. Needless to say, even with our success, it is still a work in progress...]

Finally, I wonder if flipping changes in any way the experimental work the students can do or the way the experimental work is organized?

[The final question on experimental work is a tough one to answer. I am struggling with the effective use of labs and demonstrations across all levels and disciplines of science.

I feel demos are often more "wow!" than “why”? I also find that while students enjoy participating in labs, many lack the desire to fully comprehend the application of theory to the labs, only analyzing data and interpreting results if there is some sort of summative evaluation associated with it. We are very much of the opinion that chemistry is a “hands-on" discipline and in that regard are trying to incorporate more inquiry and activity-based learning in hopes that we can make interpreting lab activities and data more relevant. I have also toyed with the idea of having "lab checkpoints" and "lab summatives" as well. Like many things, it is an on-going process. However, this is something that I have observed and have been working on independent of the flipped learning. I will say that the flipped method does allow us more time to "experiment" with our experimenting!]

References and notes

  1. CÉGEP is a publicly funded pre‑university college in the province of Québec's education system.
  2. Wikipedia.org for: Keller plan; mastery learning.    ∎

David Cash (retired) <david.cash@mohawkcollege.ca>
Mohawk College
Hamilton ON

Re: ‘Whoosh Bottle’ scare

I still do this demo with all the safety preps that John Fortman and Bill Deese recommend — but I add one more important thing. Tape the bottle with clear plastic packing tape. And never use a square or rectangular bottle — I have seen them blow up because they are stressed.

I was running a workshop — either a Woodrow Wilson or Flinn week, can’t remember — where each person was required to do a demo. One person brought a rectangular bottle untaped. I told her it was not a good idea to use this shape of bottle. She insisted on using it. I made her tape it thoroughly and put it behind a blast shield. I made her wear gloves. I told the other teachers that they should not use this type of bottle. By this time, the person doing the demo was not happy. She said it was overkill. Well you know where this is going. The tape held as the bottle fractured.

The new 5-gallon bottles have handles on the side. I wonder if there are more issues with these new bottles?

Lee Marek (retired)
Naperville North High School and University of Illinois at Chicago
Chicago MI

Re: ‘Whoosh Bottle’ scare

I was happy to see the careful discussion of the ‘Whoosh Bottle’ Demo in the March 2015 edition. I agree with all the cautionary advice in there.

In fact, when I first became aware of the demo in 2001, I tried it ONCE. It scared me to see how close to an explosion the event came…. And I started searching for a safer alternative.

I first presented the ‘Whoosh Tube’ variation at BCCE 2002 and then at ChemEd 2003. Imagine my pleasure as a retired teacher when I watched Sharon Geyer and Micaela Ferreira from Pomfret School, Pomfret, Connecticut do an excellent job of demonstrating it at ChemEd 2013. [Instructions on next page and online (link above).]

Both Sharon and I use a polycarbonate tube of about 1 m or more in length and at least 2.5 cm in diameter. Since the tube is open at both ends, any pressure wave will exit the tube before the sides are stressed. The use of rubbing alcohol (70% iso-propyl, 30% water) slows down the combustion well, and standing waves form in the tube producing great sound effects.

Although I think that this is safer than the ‘Whoosh Bottle’ demo, the following advice is just a starting point for demonstrators to help them consider reasonable safety precautions. Each situation is different and, as in every demonstration, it should be practiced with care BEFORE doing it in front of an audience.

Doug De La Matter (retired) <doug.delamatter@bell.net>
Madawaska Valley District High School, Barry’s Bay ON