Possible Worlds was directed by Robert Lapage, who is not only (my opinion) Canadian's finest film-maker, but also our preminent stage director. I've discussed his work with a few theatre types, in regards to his scene transitions. They suggested a stage director is forced to be more inventive when it comes to lapsing of time. Where a hack filmmaker might simply rely on a dissolve (see Paxton's awkward handling in Frailty), a stage director tries to come up with something more organic, aiding them when that big film contract comes along. Of course Welles did come out of the theatre world, and was also quite adept at scene transitions. Two other LePage films worth seeing are No, and Le Confessional. The latter film is known for constantly jumping between decades in a single shot.