Saturday, April 05, 2008

Classroom Chemistry Demonstrations

The story is in the news this weekend about a chemistry demonstration in a High School science class here in New Brunswick where a routine demonstration resulted in the injury of a student. Without a doubt this is the worst case scenario short of burning down the school. No teacher would accept any chance that a student could get hurt as a result of a demonstration. But accidents happen. We need to hope that this was a true random accident and pray that the student has a full recovery. It is clear that the teacher is an exceptional, caring teacher and that this incident has deeply affected him, we need to pray for him as well.

It is my position that there is just not enough information out yet to allow us to make anything other than the most general comments. We need to be careful not to overreact or make assumptions.

The link below to the CBC article has some interesting comments in addition to the article from students in support for the teacher. That is very revealing.



This is all part of a cost-benefit calculation that every science teacher has to make. The primary consideration is always "Can I do this safely?" after that comes "Will the students learn anything from the demonstration", "Will the time and effort spent setting up, conducting and cleaning up the demonstration be justified by the facilitation of learning or am I just amusing the students?"

In my case I really agonize over this. I have always used a chalkboard because I felt that writing on the board slowed me down and showed the students that I too had to cope with how to write and draw scientifically. I have always stopped and told stories because I believe that for a lecture to work there must be "intellectual rest periods". I have always done demonstrations both to create breaks in the lecture and to emphasize points that are best learned by observing not being told. In the back of my mind however the rational part of my brain is always yelling "you have 36 hours to teach this material and you are going to blow 30 minutes on a demonstration? ... you do not have time for this".

In my experience demonstrations are an academic highwire where the teacher can look really stupid in front of his students and if something goes wrong people might get hurt. I remember that I used to burn small amount of sulphur in class to show them the cool blue flame. Then one year one of my students turned out to have an extreme allergic reaction to sulphites and she just barely made it to the hallway to escape the slight fumes from the reaction.

I can only see this going one way when it comes to the public schools. All classroom demonstrations will be stopped and the students will be shown videos of the demonstrations. I just do not see the public accepting any risk that when they send their children to school that they might get hurt in a classroom. I hope not, but I really feel that is where we are going.

Risk is one of those things that we have hardwired into our minds. We are usually well aware when we are doing something risky and the response to stress is heightened awareness and more deliberate action. The thing is that we are also conditioned to cope with stress as it becomes a routine part of our lives. In some peoples lives the riskiest thing that they will do during a day is drive down a highway. In spite of that years of coping with the stress of driving now allows them to eat, talk on the phone and drive all at the same time. It is not that they are better drivers ... they are simply conditioned to cope with the stress. Some people would argue that this leads to complacency and accidents. I hope that was not the case this time.

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