“…For example, they differ in terms of the following variables, all of which are essential for the introduction of referents: whether the narrator is familiar with the contents of the narrative, whether the addressee (adult or child) is physically present, and especially whether s/he shares knowledge about the referents. As has been shown by studies devoted to referential communication, variables related to the interlocutors' competence, including academic status, deafness, co-operativeness, affect speakers' performance (e.g., Anderson, Yule & Brown 1984, Bonitatibus, Godshall, Kelley, Levering & Lynch 1988, Brownell, Trehub & Gartner 1988). In addition, even in comparable communicative situations, children are asked to perform very different tasks, e.g., naming referents, describing unrelated pictures, narrating picture sequences, narrating films during versus after presentation, etc.…”