Comparing these examples with their parasitic gap counterparts in (96) and (97), we see that the speaker-hearer's linguistic intuition suffices to account for a descriptive fact. A consequence of the approach just outlined is that the notion of level of grammaticalness can be defined in such a way as to impose a parasitic gap construction. With this clarification, a descriptively adequate grammar is rather different from nondistinctness in the sense of distinctive feature theory. Analogously, a case of semigrammaticalness of a different sort is to be regarded as the ultimate standard that determines the accuracy of any proposed grammar. Nevertheless, relational information is necessary to impose an interpretation on a corpus of utterance tokens upon which conformity has been defined by the paired utterance test.
see also: WikiPedia -- Chomskybot