It's always a good idea to provide a context to your query. Do you have any? If so, is it of historic nature or is it more uo-to-date?
I'm afraid I can't come up with a Polish version, but what might come in handy is some rough translation such as edukacja otwarta or wolna edukacja. Though, the latter might be associated with learning on your own.
Basically, open teaching is about choice of environments in which teaching is being conducted.
I didn't provide context because it really does not help much in this case :/
The text in which I found this term is about promoting cooperation between education institutions and making it easy for students to study in different european countries. "open teaching is about choice of environments in which teaching is being conducted." could you specify? I don't really understand what you mean
That's what "choice of environments" is about; studying abroad in this context. In other, it could mean studying in another city or university. Back in the day in Scotland for example, professors would set up their tents and teach students who flocked together. That's also open teaching; only in its initial form.