Subject: Do We Want to Talk about the

Posted by Richard Turnock on 2/25/2006
In Reply To:Do We Want to Talk about the Posted by John Gunkler on 2/9/2006

Message:

>>>>>>>>>from John Gunkler:

I am afraid that I'm not yet comfortable with a Ferris Wheel as a metaphor for a feedback loop. While it captures the notion of things going around a circle and returning to the beginning, I don't see how it illustrates the key idea behind a feedback loop -- namely, the idea that what returns through the loop somehow affects what next is sent through it. You only have "feedback" when what you send out now somehow comes back to influence what you send out later.

>>>>>>>>>>>>>>>>>>>>



I’m suggesting we need a way to understand the concept of a feedback loop without using an example of a feedback loop or building a model.



One reason metaphors are uncomfortable is that they say “A is B” when that is a literal false statement. So, yes, a ferris wheel doesn’t literally illustrate the key idea. We have to manipulate the ferris wheel and transfer the characteristic to feedback loop.



I like the example you developed. That would be useful at the end, after scaffolding through the levels of the metaphor to the concept of a feedback loop, and then the students actually get to build a model.



What about this:

People getting off the ferris wheel affect what happens next by giving the next riders information about what they are suppose to do while on the ferris wheel and those instructions change over time. Maybe have the students imagine they’re riding the ferris wheel as things change. When the ferris wheel stops to let someone off/on, the people on the ferris wheel exchange information at accumulations, flows and variables around the ferris wheel loop.



Richard