analogies

A few days back the Math lecturer in my college was telling me about her experience in trying to show the larger picture during one of her math lectures. She gave some analogies, brought in other stuff. End of the year, a student told her "you just talk, you don't teach any math"

My experience with analogies is similar. During a lecture on adsorption, I mentioned that this was one way heterogenous catalysts work...a molecule fixed on a solid.....etc. an analogy just struck me and I said "If you go to pick your friend up at the railway station, he gets down from the train and starts looking for you--you reach the platform and wander around looking for him, it will be a looong time before you meet up. Instead, if he gets down and stands still, you just walk to the platform and find him in a few minutes."

The term exam question on adsorption got me answers all about railway stations. I swore NEVER to use analogies again.