Science fiction movie? Scientists creating a miniature world

[Vince]

I don't remember much of the movie, but I suspect it's a film from the 80's, maybe 90's, I've seen it once when I was a kid.
It's about scientists who create a miniature artificial world as an experiment. The end of the movie shows that the scientists who did this are part of a miniature world (place) which in turn was part of an experiment just alike. In the real world humans created a lot of these miniature worlds to study the actions of it's inhabitants (humans too), and said miniature world was the only place that conducted the same experiment as well.
I'm not sure about this part, but I believe they 'pulled' the scientists out of their world to tell them about it, however: I'm not completely sure this happened.

Does anyone remember the name of this movie?