String theory being called that is an abomination, and it should be throughly labeled as string hypothesis until such time as they've got evidence. Models that haven't made predictions yet should be clearly marked as such. And I'd point out that one can have great use out of a model or law that doesn't explain mechanics, per se, but does accurately make predictions. For example, Kepler's laws of motion accurately explain and predict the motion of the planets, but make no attempt to show why those laws exist. I think the first four dimensions are fairly clear, however I think it's worth noting that with the others, it's not that the models require 11 dimensions to work, it's that the output from the mathematical models indicates those dimensions. So it's going the reverse, that's a result... a prediction trying to be verified, if you will, not an assumption of the models. Vivec may be more useful here as I know he's done coursework in all this junk more recently than I did.