DEMOS in TEACHING
I am sending to you some input on using demos. Basically, I just googled it, so 90 % of the information are other peoples’ opinions.
Of course, there is no one right view; there are many cross-sections of the teaching process.
From http://sprott.physics.wisc.edu/demobook/intro.htm (by Julien Clinton Sprott)
Demonstrations provide a concrete visual way to help explain a topic. They can be used to involve students interactively in lecture, and are an effective means to recapture students’ attention partway through a class.
Visual examples of abstract concepts provide an opportunity to illustrate the scientific method and to teach the student to relate experimental observation to scientific theory. The use of demonstrations makes the learning of physics much more enjoyable!
Good lecture demonstrations are absolutely indispensable as tools for helping students to relate physical concepts to the real world. Good lecture demonstrations also have the strength of being memorable.
By contrast, the use of lecture time to present derivations is typically ineffective. A derivation presented on the blackboard is less useful to the student than the same derivation presented in the textbook, where it can be traced through repeatedly at the student's leisure.
The least effective use of lecture time is for presenting the solutions to physics problems. The essential difficulty here is that physics problem-solving is a skill that has to be learned by repeated practice. In learning a skill, it can be useful to first watch an expert exercise that skill, but that is by no means the most important part of the learning process. If it were, the millions who watch professional sports would themselves naturally develop into top-notch players; avid movie-goers would inexorably turn into accomplished actors (who really want to direct); and the poor souls who watch televised court proceedings would slowly but surely mutate into highly paid defense attorneys.
By the way, I found even a suggestion that nowadays demos are completely useless, because there is such stuff like videos, Java applets, and labs became more sophisticated (of course, I cannot support this view).
I would say that demonstrations could have several different effects.
1. A “wow” effect. When something unusual or unexpected or beautiful is happening it has a positive emotional effect on the audience. But the goals of the “wow” effect might be different. For high school students it can make them to think about a career as a scientist.
For college students this stage is in the past, we got them already in a class, but the “wow” effect can be used as a recollection tag; if a demo is linked, for example, to a specific term, later on it can be used to start the process of recollection of the material.
2. An “I got it” effect. When words are a week tool, demo can be used to illustrate what we mean. Every part of the demo can be associated to a term, law, object, etc.
3. A “start thinking” effect. A demo can be used to start a discussion, to pose a question.
4. An “it works” effect. A demo can be used to show that just done theoretical prediction is working.
5. An “it is fun” effect. If a lecture is build up from demos, like a demo theater.
6. An “I got confused” effect, if a demo is not connected to the material.
7. An “I got bored effect”. If a lecture is build up from demos, like a demo theater, but demos are not connected to each other or to the material or to the future tests.
8. A “get awake” effect. It is known that after 15-20 minutes of listening to a speaker one loses 50-80 % of attention. At that point, a demo brings an opportunity to refresh attention. However, to achieve similar effect any distraction can be used; a joke (if it is only the first for twenty minutes), a video clip, making the audience to discuss something (anything works), making the audience click a clicker or clap hands, etc. As any energizing tonic, the use of demos should not be overdosed.
When thinking about using a demo, one can think of how does the demo help students to get better prepared to the final, is the demo reliable, how long does it take to set it up and disassemble, how much time would be needed to learn the demo, is the demo the best way to achieve the goal or another tool can be used more effectively (a video clip, a simulation, a road trip, a problem solving demonstration, etc)?
I welcome any comments or ideas on the usage of current or wanted demos, what would you like to change, what new demos would you like to have, what physical effects or ideas you would like to demonstrate?
Have a good teaching,
P.S. Interesting site having videos of demos