Experimental art is that which takes unfamiliarity as its dominant—even to the point of schism.
The experimental artist wants her artwork to be different from all the other artworks around her. She desires that her results be unusual, unfamiliar to the point of looking peculiar, perplexing. She may be drawing on conventions, she may be working inside one or more traditions. But her conventions and traditions are not dominant ones; they are, perhaps, older ones, or unpopular ones. Or she may be importing ideas and conventions from one medium into another, where they are not well known.