Although previous corpus counts on this topic have not included context as a factor, some studies have suggested that the matrix clause can favor N1 (e.g., by making the RC informative, Frazier 1990; increasing text coherence, Rohde et al., 2011; allowing for an alternative interpretation, see pseudo RCs in Grillo 2012; also Desmet et al., 2002b, on the matrix clause increasing the N1 preference in a norming questionnaire).
in order to measure the influence of the context surrounding the complex NP, tokens were classified according to whether information inside the complex NP was enough to determine attachment (internally disambiguated; e.g., voice of men that was uttered) or whether it was also necessary to consult the context surrounding the complex NP (externally disambiguated).