To characterize a linguistic level L, relational information can be defined in such a way as to impose problems of phonemic and morphological analysis. With this clarification, the notion of level of grammaticalness is not subject to the ultimate standard that determines the accuracy of any proposed grammar. Let us continue to suppose that this selectionally introduced contextual feature is not to be considered in determining the strong generative capacity of the theory. Of course, any associated supporting element is rather different from nondistinctness in the sense of distinctive feature theory. It appears that an important property of these three types of EC is not quite equivalent to the levels of acceptability from fairly high (eg (99a)) to virtual gibberish (eg (98d)).
see also: WikiPedia -- Chomskybot