Is it ethical to steal another teachers creative ideas, and when confronted to lie about it?
Favorite Answer
It’s nice to know you work with people you can’t trust, isn’t it.
(note the sarcastic tone there)
You have done all you really can, confrontation usually works as you can tell from body language if the person is uncomfortable about talking about it, its easy to spot a lie. I would have to advise that you keep your ideas more or less close to yourself if this has got to you. Be careful who you trust. Maybe in the future you should miss out the “cherry on the top” in your lesson plans when discussing it with a workmate.
In the case of college level classes, if you can find any proof (e.g. some aspect of the lesson that could only have come from you) it could merit asking the department head for advice.