Suppose, for instance, that the descriptive power of the base component appears to correlate rather closely with problems of phonemic and morphological analysis. Thus the appearance of parasitic gaps in domains relatively inaccessible to ordinary extraction raises serious doubts about a corpus of utterance tokens upon which conformity has been defined by the paired utterance test. It must be emphasized, once again, that a subset of English sentences interesting on quite independent grounds is not subject to a general convention regarding the forms of the grammar. Nevertheless, most of the methodological work in modern linguistics cannot be arbitrary in an abstract underlying order. Let us continue to suppose that this analysis of a formative as a pair of sets of features is, apparently, determined by a stipulation to place the constructions into these various categories.
see also: WikiPedia -- Chomskybot